optional module 4: medicinal chemistry Flashcards
1
Q
what diseases do mosquitos spread
A
malaria, dengue fever and the zika virus
2
Q
how did insulin used to be exctracted
A
from the pancreas of cattle to treat children suffering from diabetes.
3
Q
how is insulin extracted today
A
synthesised using bacteria or yeast to meet the public deamnd
4
Q
where are synthetic drugs produced
A
in a laboratory, using chemical reactions to produce and isolate the acrive medicinal agent
5
Q
where was asprin first extracted from
A
from the bark of willow trees,
6
Q
how is asprin produced now
A
now made commercially by reacting acetic anhydride with salicylic acid. The product, acetylsalicylic acid, is then isolated from the other product acetic acid and purified from any other contaminants.
7
Q
drug synthesis pathway
A
drug discovery
pre clinical
clinical trials (phase I, II, III)
review
manufacturing phase IV
8
Q
what is combinatorial chemistry
A
a laboratory method that involves using robotics to synthesise thousands of different compounds at a time, usually peptides or small molecules. The compounds can then be tested for effectiveness, and then kept for further testing or modification, or discarded. With this highly automated process, large volumes of molecules can be synthesised and tested in a short period of time, but it is more of a trial-and-error approach, resulting in a large amount of molecules made that have no activity. Although it is difficult for scientists to mimic natural processes, combinatorial chemistry is proving to be making new advancements in drug discovery.
9
Q
what is a double blind test
A
where a placebo is offered to one group of patients while the other group recieves the drug
10
Q
what is a placebo
A
a pill, lotion or injection that does not contain the active ingredient that the drug has, and is used to see if the drug does have a measurable effect compared to not using the drug.
11
Q
methods of drug administeration
A
Ingestion by mouth (e.g. pills or syrups).
Injection with a syringe under the skin into fat or muscle tissue or bloodstream.
Inhalation by mouth or nose (e.g. as with an inhaler or nebuliser).
Absorption through the skin (e.g. medicated lotions or stick-on patches).
Absorption in the rectum or vagina (e.g. suppositories).
Applied into the ear or eye (e.g. drops of prepared solutions).
12
Q
what does oral medicine require
A
the medicine to be absorbed by the digestive tract
13
Q
what is the speed and ability of the body to absorb medicine called
A
metabolism
14
Q
what determines method of administeration
A
dosage (grams or millilitres)
frequency of administeration
tolerance of the drug
side effects
15
Q
what can help to prevent against addiction
A
A slower, time-released method, such as with oral ingestion or a skin patch, can help to keep the levels of medicine in the body lower and more consistent, and avoid dependency.
16
Q
in animals, the theraputic index is the lethal dose of the drug for
A
50% of the population (LD50) divided by the minimum effective dose for 50% of the population (ED50)
17
Q
in humans, the theraputic index is the toxic dose for
A
50% of the population (TD50) divided by the minimum effective dose for 50% of the population (ED50)
18
Q
the theraputic window is
A
the range of dosages between the minimum amounts of the drug that produce the desired effect and a medically unacceptable adverse effect
19
Q
theraputic index
A
the effective window where the dosage of the drug is most active
20
Q
lethal dose
A
the dose of the drug that is enough to kill half of the population
21
Q
toxic dose
A
upper limit of the therapeutic window
22
Q
doage
A
amount of drug given
23
Q
aims of drug administration
A
dosage, tolerance, addictiona nd side effects
24
Q
what is bioavailability
A
the fraction of the administered dosage that reaches the target part of the human body
25
drug receptor interactions are based on
the structure of the drug and the site of the activity
26
therapeutic index for animals:
LD50
---------------
ED50
27
what is the ED50
the effective dose for 50% of the population
28
what is the LD50
the amount of drug required to kill 50% of the animal population
29
in humans, the LD50 cannot be determined experimentally and animals raise ethical concerns so what is used instead
the toxic dose
30
the smaller the value of the therapeutic index...
the more dangerous the drug because the minimum effective dose and the toxic or lethal doses will be similar
31
how can drugs be administered
enteral (oral, sublingual, buccal, rectal)
parenteral (injection)
topical (enepidermic, epidermic, insufflations, instillation, irrigation, swabbing)
32
what is subcutaneous injection
directly under the skin, usually for small volumes of drugs, eg insulin and vaccinations. intramuscular is usually injected into the arm, leg or buttocks and used for larger volumes of drug or when a vein cannot be found if the drug irritates veins
33
intravenous injection hs the most rapid effect as the drug enters the bloodstream directly. when a medicaiton is administered intravenusly, the bioavaila bility is
100%
34
why is bioavailability not always 100%
acidity of the stomach or small intestine may destroy some of the drug, the drug may not be completely absorbed or it might even be absorbed by the bacteria in the small intestine
35
factors that affect bioavailability
degree of ionisation
solubility in lipids
form of dosage
concentration of dosage
36
why must drugs have some polarity
to reach blood (polar solvent)
37
why must drugs have some non polarity
to pass through the cell membrane
38
polar functional groups
hydroxyl, carboxyl, amino
39
non polar functional groups
alkyl side chains
phenyl rings
40
if a drug is administered orally, then it will generally dissolve
within the poalr environment of the contents of the stomach
41
if the drug is not very polar
it might bind to food particles instead, preventing it from being absorbed. this is why drugs are sometimes required to be taken either with food or on an empty stomach to ensure better absorbption (and thys greater bioavailability)
42
what is tolerance
a decrease in effectiveness of a drug as it is used more
43
dependence can occur when
reducing or stopping the dosage of a drug leads to physical withdrawl symptoms
44
heroin is a derivative of
morphine
45
what is a placebo
does not contain the active ingredient of the drug and is used to compare to the drug
46
what is the type of test called when neither the test takers or the researchers know which partakers receive active substance and which ones receive placebo
double blind
47
what is bioavailability
the fraction of an administered dose of the medicine that reaches the target site.
48
on a molecular level, drugs interact with the
receptors in cell cytoplasm
receptors in cell membranes
49
what did asprin used to be prepared from
willow bark
50
what is asprin prepared from now
salicylic acid and acetic anhydride/ethanoic anhydride
51
what type of reaction forms asprin
esterifcation to produce acetylsalicylic acid (asprin) and acetic acid
52
what does esterification require
acid catalyst
53
how can aspirin crystals be collected
by filtration (gracimetric or vacuum filtration) when the mixture cools in an ice bath following the reaction
54
how is purity of a product improved
recrystallisation
55
what is recrystallisation
generally involves taking the dried white crystals that were obtained and dissolving them in warm 95% ethanol in a flask. When the crystals have all been dissolved, an equal volume of water is added and the contents cooled on ice until the aspirin crystals recrystallise (and return to white). The sample is then filtered again, and recrystallisation can be repeated many times to ensure improved purity of the sample. This process works by removing impurities by dissolving them in ethanol, which has polar and nonpolar properties. The impurities will dissolve and be rinsed away with the ethanol/water mixture, leaving behind the pure aspirin crystals, which have a melting point of 136°C, meaning it will become a solid when cooled to room temperature.
56
process of recrystallisation
dissolve compound in a minimum amount of hot solvent (ethanol)
allow solution to cool to room temp so that crystals form slowly
filter crystals by suction using a hirsch or buchner funnel. wash crystals with fresh, cold solvent
57
melting point range
the sample can melt over a range of temps
58
an impure sample will have a melting point lower than the...
theoretical temperature
59
why do impure substances have lower temperatures
they have impurities that disrupt the crystalline structure, weakening the attractive forces between particles. the lower the purity, the greater temp difference from the theoretical melting point and the broader the melting point range
60
how can purity be tested
infrared spectroscopy
61
analgesics
medicines that provide relief from pain (analgesia). Some different analgesics include aspirin, acetaminophen/paracetamol and opiates. Some analgesics work at the site of the trauma while others work in the brain to alter the perception of pain.
62
what is asprin used for
pain reliever, fever reducer and anticoagulant
63
potential side effects of asprin
can irritate the stomach and lead to ulcers
causes blood to thin
64
how is asprin often prescribed
people with a risk of heart attack or stroke
during pregnancy to reduce the risk of certain pregnancy complications
to improve circulation for people with diabetes
65
how does asprin work for pain relief or fever
asprin stops the enzyme that produces prostaglandins which is cyclooxygenase.
66
what happens when we experience physical trauma
the cells in our body respond with a series of steps that ends with the production of chemical substances called prostaglandins. the cells in our body respond with a series of steps that ends with the production of chemical substances called prostaglandins.
67
analgesics are
pain relievers
68
antipyretics are
fever reducers
69
what is asprin, an analgesic or an antipyretic
both
70
why is blood slightly viscous
due to the presence of dissolved fats, proteins and other components.
71
what is coagulation
when platelets clump together/clot
72
what happens in haemophilia
the blood doesnt clot well so the person can lose a lot of blood
73
what happens if blood vessels becom blocked
parts of the body cant recieve nutrients. plateltes also contirbute to blockage by percieving it as damage.
74
If the blockage occurs in the artery leading to the heart,
the heart begins to pump harder to draw more blood toward itself and the heart muscle becomes damaged. This is called a myocardial infarction, or commonly a heart attack.
75
If the blockage occurs in the artery leading to the brain,
blood and the oxygen it carries do not reach the brain, causing damage. This is called a stroke.
76
asprin slows down clumping of platelets so they...
anticoagulate
77
what is a prophylatic
to slow or prevent the formation of a blockage in the first place.
78
how can asprin be chemically modified to a salt to increase its solubility in aqueous solutions
By dissolving the acetylsalicylic acid in sodium hydroxide, the hydrogen on the carboxyl functional group is replaced by a sodium ion, as shown in the reaction below, to make sodium acetylsalicylate, sometimes called soluble aspirin.
79
why is the sodium acetylsalicylate product is more soluble in water than the aspirin molecule
ions have a stronger attractive force to the dipoles in water molecules than the intermolecular forces of the carboxyl functional group
80
what is the benefit of having a product with greater aqueous solubility
it means that orally ingested sodium acetylsalicylate will reach the stomach more quickly
81
why is The bioavailability of soluble aspirin, however, is almost the same as the insoluble form
because the ionic salt reacts with stomach acid to produce (insoluble) aspirin.
82
describe a method to inrease the bioavailability of asprin
administer the drug intravenously
83
what type of effect do asprin and alcohol have
a synergistic effect:
each drug has a higher medicinal effect when taken in combination than they would when taken separately.
84
why should you not consume asprin and alcohol simultaneously
to avoid te increased risk of stomach bleeding or other toxic effects
85
how do communicable diseases usually spread
through bacteria or viruses
86
bacteria are
single-celled organisms that divide by binary fission within the organism that they have infected.
87
how can bacterial infections be treated
with antibiotics, like penicillin that stop its growth and production
88
viruses are
small capsules of DNA (deoxyribonucleic acid, which is genetic material) that require a host organism in order to replicate. Viruses are much smaller than bacteria and do not contain the organelles necessary to divide on their own.
89
how can viral infections be treated
immunization the only option really
90
how is industrial pencillin produced
its fermented in large stainless steel tanks in sterile environments. In order to produce a stressful environment, scientists provide penicillin with lactose sugar, rather than glucose sugar that the fungus prefers as a food source. The temperature, pH and other nutrients added to the batch also ensure that the fungi are under stress. then the pencillin is seperated from the mold and is purified for use as an antibiotic medicine
91
how is the fungi held under stress
lactose sugar (not glucose) temperature, pH and other nutrients
92
what is the mold that produces pencillin called
penicillium mold
93
CORE STRUCTURE OF PENCILLIN
(D.2 synthesis of pencillin)
94
what is the becta-lactam ring
the func group of penicillin. important for the action of pencillin in preventing bacterial growth
95
what can benzyl penicicillin treat
syphilis, meningitis and other bacterial infections
96
if pencillin contains a benzene ring, what changes in its treatment
it must be injected as benzene is non polar so is not water soluble enough to be absorbed by oral ingestion
97
whats penicillin V
oxygen before the benzene ring
98
benefit of pencillin V
slightly more solubility so can be prescribed as an oral antibiotic to treat minor infections like tonsilitis. is stable in an acidic environment
99
which environment is pencillin g not stable in
acidic, so it cannot be taekn orally and must be injected to have better bioavailability
100
how is ampicillin produced
by chemically modifying the R group to include an amino group.
101
benefit of ampicillin
The presence of this amino group allows ampicillin to better penetrate the cell walls of bacteria and thus has greater action on stopping the growth of bacteria for respiratory infections. The amino group also allows for greater solubility in water, so ampicillin is often prescribed orally, rather than intravenously.
102
what are cell walls made of
peptidoglycan, a polymer made of sugars and amino acids, aka murein, sandwiched between two lipid layers.
103
what would happen without a functioning cell wall in a bacterium
it would not have the rigid structure required to function and would instead rupture, causing the death of the cell.
104
what is the cross linking of cell walls
covalent bonds holding the layers together (common in polymers)
105
benefits of cross linking in cell walls
additional structure and rigidity
106
how does cross linking occur
by the action of certain enzymes like transpeptidase. the penicillin binding protein (PBP). the beta lactam ring effectively binds to the transpeptidase
107
how does cross linking occur
by the action of certain enzymes like transpeptidase. the penicillin binding protein (PBP). the beta lactam ring effectively binds to the transpeptidase (PBP) and interferes with the action of the enzyme, not allowing the cell wall to be cross linked. a lack of cross linking will have too much water entering via osmosis causing the cell to burst.
108
sme bacteria are capable of producing enzymes that destroy pencillin
penicillinase or becta-lactamase
109
how does penicillinase work
to break the beta-lactam ring in the penicillin molecuel, thus rendering it ineffectice in binding to transpeptidase (also known as the penicillin binding protein)
110
having a bulkier larger r group seems to make penicillin more
resistant to penicillinase, so naturally-occurring penicillins can be chemically modified to make penicillin more effective at stopping the growth of bacteria.
111
waht is opium
the dried latex of the opium poppy
112
what is latex
milky fluid produced by some flowering plants and contains a mixture of polymers, sugars, oils and proteins. Latex from plants can be used to make a variety of consumer products including balloons, chewing gum and paint. Opium latex was observed to have medicinal properties as early as 5000 BC
113
opiates
generally refer to naturally occurring analgesics obtained from the opium poppy or synthetic derivatives made from the naturally-sourced medicine. Examples include morphine, codeine and diamorphine (heroin).
114
opioids
generally refer to synthetically produced drugs that mimic the action of naturally occurring opiates. Examples include oxycodone and hydrocodone. These drugs have been under a lot of legal and ethical scrutiny for their highly addictive nature.
115
cultivation of opim poppies
originally mediterranean
now turkey, england, india for pharmaceuticla compnies legally.
illegal cultivation has occured in myanmar, thailand, laos since ww2, and has grown in afghanistan in recent years (largest producer of illegal opium)
116
active medicinal ingredient in opium is
morphine
117
opium latex contains about
12% morphine so it must be refined to purify and make the sample more potent
118
traditional puppy cultivation involves
making incisions in the seed pod and collecting the dried latex. The latex is then processed to extract the morphine, which can then be taken intravenously or orally.
119
morphine can also be used to make
codeine, an analgesic used to treat a mild-to-moderate degree of pain, and heroin, a highly addictive analgesic, which is illegal in many countries.
120
what is diamorhphine known as
heroin
121
opiates must travel to
the brain (through blood as they have polar functional groups) where they interfere with nerve impulses. however the brain is surrounded by a layer of lipids or fats which are highly nonpolar. there must also be enough nonpolar functional groups
122
what functional groups does morphine have
two hydroxyl which add polarity and water solubility to the structure.
123
how is morphine prescribed
Morphine is prescribed orally in a tablet or liquid or by intramuscular or intravenous injection.
124
bioavailability of oral morphine
30%
125
codine functional group
one hydroxyl substituted with an O bonded to a methyl alkyl functional group which forms an ether and therefore slightly decreasing the polarity and water solubility compared to morphine (allowing for a higher bioavailability)
126
bioavailability of codeine orally
90%
127
cons of codeine
less effective at binding to receptors in the brain and therefore has 1/10 the strength of morphine, so it is only suitable for mild to moderate pain.
128
diamorphine functional groups
two hydroxyl substiuted with O boinded to an acetyl side chains which forms 2 ester groups and greatly reduces the polarity and solubility in water compared to morphine and codeine
129
bioavailability of diamorphine orally
less than 35% so generally taken intravenously
130
with the decrease in polarity of diamorphine what happens
diamorphine can pass into the brain much more easily than both morphine or codeine. It also binds to the receptors in the brain more effectively than both morphine and codeine, making diamorphine have 4-5 times the strength of morphine.
131
opium latex contains how much codeine
3%
132
what is codeine sometimes referred to as
methylmorphine since one hydroxyl functional group is replaced with a methyl alkyl group via a methylation reaction.
133
what is codeine sometimes referred to as
methylmorphine since one hydroxyl functional group is replaced with a methyl alkyl group via a methylation reaction which makes an ether linkage. This reaction is actually reversed in the liver when the body is breaking down the codeine for elimination.
134
methylation diagram codein
d3
135
which is not found in opium latex
dimorphine (heroin)
136
how is dimorphine made
it is only made synthetically by reacting morphine with ethanoic acid in an esterification reaction. The hydroxyl functional groups on the morphine molecule each react by a condensation reaction with the carboxylic functional group on the ethanoic acid. The result is an ester linkage and the elimination of water.
137
what happens when the body recieves trauma
a chemical pathway occurs with the end result being the production of prostaglandins.
138
what do prostaglandins do
increase the body's temperature, causing a fever, and are also part of producing the sensation of pain.
139
what causes the sensation of pain
by the direct action of prostaglandins on the nerve endings locally at the site of the trauma or by acting on the perception of pain in the central nervous system in the brain.
140
what happens when the CNS receives a pain stimulus from the nerve endings at the site of a trauma
the pain signal is transmitted through the nerve cells, called neurons, to the spinal cord and then the brain. Neurons can communicate to one another using chemicals called neurotransmitters, to transmit the signal faster and across small gaps between neurons, called synapses, where they interact with receptors on the neuron on the other side of the synapse. Specific parts of the brain are then stimulated to give the sensation of pain.
141
how do opiates work
by interfering with the neurotransmitters and receptors in the transmission of the pain signal across
142
what are endorphins
work as natural pain relievers
143
Endorphins bind to what
endorphin receptors (also called opioid or opiate receptors) in brain cells to intercept the pain signal.
144
what do opiates bind to
the same endorphin receptors since they have the same chemical structure as endorphins (so the body cant tell)
145
what is the implication of "dopamine is a neurotransmitter that is produced when the endorphin receptor binds to a natural endorphin or to an opiate."
The release of dopamine causes feelings of pleasure, which adds to the addictive nature of opiates.
146
side effects of enorphin receptors
All three receptors respond with analgesia (pain relief), but each one also produces other side-effects, ranging from hallucinations and anxiety to respiratory depression, nausea and constipation. These side-effects are the result of chemical changes that occur in the body in response to the binding of the opiate or endorphin to the endorphin receptor.
147
which chemicals can bind to endorphin receptors
morphine codeine and diamorphine
148
codeine is what strength of morphine
1/10
149
how is codeine turned tom orphine
must first be metabolised in the liver back into morphine. This conversion is quite slow and other products are also made, which have no medicinal effect.
150
why is dimorphine faster at crossing into the lipid layer that surrounds the brain
contains more nonpolar functional groups than morphine or codeine,
151
Diamorphine can only bind to one receptor, so the effect of diamorphine is
is immediate, but does not last long.
152
morphine most common method of administeration
Oral tablet or liquid (30% bioavailability).
Intramuscular or intravenous injection (100% bioavailability).
153
codeine most common method of administeration
Oral ingestion (90% bioavailability).
154
diamorphine
Oral ingestion (35% bioavailability).
Intravenous injection (100% bioavailability).
155
morphine relative strength
1
156
codeine relative strength
0.1
157
diamorphine relative strength
4-5
158
morphine common medicinal uses
Quick moderate to severe pain.
Sedation for minor surgical procedures.
159
codeine common medicinal uses
Mild pain.
Cough suppressant for non-productive cough (one that does not clear mucus from the airways).
160
diamorphine common mediicnal uses
severe pain
161
morphine adv
Quickly relieves pain.
Mild side effects.
Option for convenient administration (oral ingestion)
162
codeine adv
Suitable for mild pain.
Drug is slowly metabolised, so fewer doses are required.
Convenient administration.
163
diamorphine advantages
Very quick relief from pain.
164
morphine disadv
Moderately addictive.
Withdrawal if taken for extended periods.
165
codeine disadv
Addiction is possible.
166
diamorphine disadv
Highly addictive.
Must be injected.
Withdrawal if taken for extended periods.
Drug metabolises quickly, so frequent doses are required.
167
use of morphine example
Morphine is used for moderate to severe pain, such as following surgery, during childbirth or after breaking a bone. Morphine can also be used effectively for sedation in minor surgical procedures, such as during wisdom tooth surgery.
168
codeine use example
Codeine, the mildest opiate, is prescribed for minor pain, such as a headache, but is also used as a cough suppressant. Codeine is metabolised slowly by the liver back into morphine, making it useful as a long-lasting analgesic for low levels of pain. Some people, however, are able to metabolise codeine very quickly, converting it to morphine at a dangerous speed, so codeine cannot be prescribed for all people.
169
diamorphine use
The use of diamorphine as a treatment for severe pain is controversial, due to its highly addictive nature. Since it is a stronger analgesic than morphine, it can be administered at lower doses. It is effective in alleviating severe chronic pain, such as for patients in end-of-life stages (palliative care) suffering from terminal illnesses. It is also used for pain relief following childbirth by caesarian section and even in children suffering from severe post-operative pain.
170
asprin acts
at the local site of trauma
171
where does morphine act/effect
morphine affects the body's central pain response in the brain, so there are more side effects. Common side effects that are mild include feeling dizzy, drowsiness, constipation and weight loss. More serious side effects include blurred vision, chest pains and difficulty breathing. Symptoms of an overdose can include constricted pupils, fever, muscle pain or spasms and severe sleepiness.
172
can you build a tolerance to opiates
yes due to the opiate receptors undergoing changes to become less sensitive to the opiates. For people taking opiates for extended periods of time, higher doses of the drug are required to have the same medicinal effect. Doctors must be careful when prescribing opiates for patients long term because of desensitisation.
173
what is tolerance
decreased medicinal effect of a drug that occurs with extended use of the same dosage. Certain medicines cause a physiological response in the body, making the same dosage of the medicine not as effective. In order to achieve the same medicinal effect, the dosage must be increased with time.
174
symptoms of withdrawl
include sweating, vomiting, muscle aches and psychological distress.
175
what is methadone
an opiate derivative that can bind to the opiate receptors but does not produce the euphoric effects of morphine. Methadone is an effective treatment option to help with tolerance, addiction and withdrawal symptoms.
176
opiates can produce what at high doses
Opiates can produce a euphoric sensation at high doses, which results in illegal use and addiction.
177
what lifestyle factors put people more at risk of excess stomach acid production eg...
A diet high in spicy, fatty or acidic foods, such as chilli peppers, coffee, citrus fruits and alcohol, can increase stomach acid production. Stress, lack of sleep or certain medical conditions can also increase stomach acid production. Eating very large meals, lying down after eating or even excess pressure on the stomach during pregnancy can push the stomach contents, including acid, up into the oesophagus, causing the same symptoms.
178
how to combat excess stomach acid production
Traditional treatments for excess stomach acid include baking soda (sodium hydrogen carbonate), aloe vera juice or ginger root tea to neutralise the acid. Apple cider vinegar, also acidic, has proven effective in decreasing stomach acid production. Currently, medicines offer quick and effective relief, either by neutralisation or by decreasing acid production.
179
what are antacids made of
Antacids can be made from a variety of compounds, but must contain a base in order to neutralise the excess hydrochloric acid produced by the stomach. The base must not be a very strong base, as it could cause damage to the mouth and oesophagus on the journey to the stomach. Many brands of antacids contain calcium carbonate, a white powdery solid that is easily pressed into a tablet, and other compounds, such as flavourings, colours and binding agents. When chewed and swallowed, the calcium carbonate reacts with hydrochloric acid in a typical neutralisation reaction:
180
antacid neutralisation reaction
CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + CO2 (g) + H2O (l)
181
give another reason for taking antacids
to support healthy bone development
182
what must be present for calcium carbonate to be well absorbed
vitamin d
183
how does calcium carbonate help with neutralising stomach acid
The products of calcium chloride, carbon dioxide and water, are neutral, so they will not further aggravate the stomach. The calcium carbonate does not neutralise all of the stomach acid, but just some, in order to leave sufficient acid for digestion.
184
what else is in antacids
Other additives are included in the antacid tablet, including flavouring, colour and antifoaming agents to decrease bloating from the carbon dioxide gas that is produced during neutralisation. Different brands of antacids use different bases, but the concept is still the same. Here are some examples of other antacids.
185
neutalisation reaction aluminium hydroxide
Al(OH)3 (s) + 3HCl (aq) → AlCl3 (aq) + 3H2O (l)
186
neutalisation reaction magneisum hydroxide
Mg(OH)2 (s) + 2HCl (aq) → MgCl2 (aq) + 2H2O (l)
187
neutalisation reaction calcium hydroxide
Ca(OH)2 (s) + 2HCl (aq) → CaCl2 (aq) + 2H2O (l)
188
neutalisation reaction sodium carbonate
Na2CO3 (s) + 2HCl (aq) → 2NaCl (aq) + CO2 (g) + H2O (l)
189
neutalisation reaction sodium bicarbonate
NaHCO3 (s) + HCl (aq) → NaCl (aq) + CO2 (g) + H2O (l)
190
why do pregnant women often get heartburn
due to excess stomach acid production and/or pressure on the stomach from a growing baby, pushing stomach contents upward into the oesophagus. Certain antacids are considered to be safe for use during pregnancy, but some are associated with increased risk of birth defects. In general, calcium- and magnesium-based antacids are considered to be safe, but sodium-based antacids are not recommended as they can lead to high blood pressure, causing other pregnancy complications.
191
how would you calculate the amount in mol of acid that can be neutralised by the base, using the mass and molar mass of the base or using the vol and conc of the liquid antacid
n = mass/mr
192
mg to g
divide by 1000
193
what is the stomach buffer system to regulate stomach acidity
Buffers are solutions that resist changes in pH when small amounts of strong acid or strong base are added. If acidic or basic foods are consumed or small amounts of stomach acid are produced or used up during digestion, the pH of the stomach contents can be 'buffered' and maintained within an optimal range of pH 1 to 3.
194
what should th esotmach pH be
1-3
195
how do you calculate the pH of a buffer solution
hendersen hasselbach equation
pH=pKa+log([A−] / [HA])
196
hendersen hasselbach equaiton
pH=pKa+log([A−] / [HA])
197
the stomach uses what in equilibrium with what
hydrogen carboante ions and carbonic acd
(HCO3- and H2CO3)
198
if pH decreases due to the release of too much acid or if acidic foods are consumed, the equilibrium will shift to
the left, using up the excess acid.
199
If the pH increases due to acid being used up during digestion or if basic foods are consumed, then the equilibrium will shift to
the right to replenish the acid.
200
stomach (HCO3- and H2CO3) equation
H2CO3 (aq) + H2O (l) ⇌ HCO3- (aq) + H3O+ (aq)
201
what is the pKa
an expression of the strength of the weak acid, in this case H2CO3. The larger the value, the weaker the acid. Carbonic acid has a pKa of 6.35. [A-] is the concentration of the conjugate base, HCO3- and [HA] is the concentration of the acid, H2CO3.
202
what does the use of antacids do to the stomach contents
increase the pH momentarily which in turn can then lead to further increased acid secretion.
203
why is chronic use of antacids is not recommended
is not recommended for long-term issues of excess stomach acid because it can worsen the problem. Antacids are effective for occasional or mild stomach acid issues, but for people experiencing severe or long-term discomfort, medicines that control the production of stomach acid are more appropriate
204
Rather than neutralising excess stomach acid, like antacids, some medicines work to stop
the production of excess acid in the first place.
205
what are the two main facctors to stomach acid production
synthesis of the acid and the release of the acid into the stomach. Drugs can work on either factor to reduce the amount of acid that makes it way to the stomach.
206
which cells is acid produced in
(specialised) parietal cells which then release the acid when required
207
why is acid made and released on demand
could cause damage to the stomach lying
208
what is the stimulus for the paretial cells to release the acid
triggered by eating food, stress or a increase in the pH of the stomach contents
209
what are the three reeptors that must all be activated to produce and release stomach acid
They are called the histamine receptor, gastrin receptor
and acetylcholin
receptors. Interfering with the action of any of these receptors will stop acid production and release.
210
agonist is
a substance that binds to a receptor and fully activates it
211
antagonist is
binds to a receptor and blocks it or prevents the action of other agonists
212
is morphine an agonist or antagonist
agonist as it binds to opiate receptors
213
is asprin an agonist or antagonist
asprin which binds to cyclooxygenase receptors to prevent their action in the pain response to trauma.
214
how to decrease acid release into the stomach is with
H2 receptor antagonist drug
proton pump inhibitors
215
example of an H2 receptor antagonist drug
ranitidine. This drug interferes with the histamine receptor and blocks its action (the 'H' in H2 antagonist stands for histamine). The result is that acid will not be produced by the cells where ranitidine interferes with the histamine receptor, since all three receptors are required to be activated in order to produce acid.
216
what is the active metabolite
the form of the drug after it has been processed by the body
217
why does ranitidine not have an immediate effect
as antacids do because there is a time delay for the liver to metabolise the drug before it is active.
218
ranitidine diagram
D4
219
The chemical structure of ranitidine has ionic charges
allowing it to dissolve very well in water, making it able to be well absorbed by oral ingestion (40-80% bioavailability), so it is generally swallowed as a tablet or as granules dissolved in water.
220
ranitidine side effects
generally headaches are reported, and very few serious side effects have been noted. The drug is effective for about 4-6 hours after ingestion, so it is generally taken twice a day. There are different doses available, depending on the severity of the symptoms.
221
what do proton pump inhibitors do
The hydrogen ions (H+) are produced in the parietal cells and released through a proton pump, while the chloride ions (Cl-) are released from a separate pump, into the stomach. The release of hydrogen ions into the stomach goes against the concentration gradient, so the proton pump is required to actively transport H+ from low to high concentration, the opposite of diffusion (when substances naturally move from high to low concentration). Proton pump inhibitors (PPIs), such as omeprazole or esomeprazole, work by irreversibly binding to the proton pump with a covalent bond, preventing it from pumping hydrogen ions into the stomach. As a result, PPIs are much more effective than H2 receptor antagonists at relieving the symptoms of excess stomach acid.
222
structure of omeprazole, a proton pump inhibitor.
D4
223
what functional groups does omeprazole have
many polar functional groups, ensuring high bioavailability when taken orally
224
why does omeprazole not have an immediate effect
can take up to 24 hours as must be metabolised by the liver before the active metabolite can have an effect on acid secretion.
225
what does the active metabolite of omeprazole do that randitidine doesnt
The active metabolite, however, binds covalently to the proton pump, resulting in a longer-lasting effect compared to ranitidine; sometimes 1-3 days for a single dose. This makes PPIs provide much longer and more permanent relief compared to antacids or H2 receptor antagonists.
226
when would omeprazole be prescribed
chronic stomach acid problems, not occasional issues
227
side effects of omeprazole
general and mild but can include fever, stomach pain, nausea and headaches.
228
FIGURE 4 D4
COMPARIOSN OF H2 ANTAGONIST AND PPI
229
span of an electron microscope
1nm-100 micrometers
230
span of light microscope
100nm - 1mm
231
bacterial infections can be treated with...
viral infections can be treated with...
antibiotics
antiviral
232
why are viruses hard to stop
small size and method of action (100x smaller than a human body cell)
233
what are viruses amde of
protein capsule containing genetic material (DNA) but no other organelles, as we typically see with other living things made up of cells. viruses therefore cant reproduce without a host cell
234
how do viruses attatch to a host cell
attatchment
penetration and viral dna is injected into the cell, the coat of the virus remains outside.
replicaation of viral dna inside host cell
new protein coats are synthesised within the host cells
assembly mature virions are assembled within the cell
cell reptures, releasing mature virus particles
235
what do bacteria need to perform cellular functions
a constant supply of oxygen, nutrients and water
236
what makes antibodies
b cells
237
what is varicella
chicken pox virus
238
how do vaccines work
a weakened form of a disease (dead or living) is injected
the body creates antigens
immunity
239
how do antiviral mediicnes work
Antiviral medicines work to fight the virus after infection occurs, whereas vaccines must be given before an infection occurs. Since antiviral medicines are given after a positively diagnosed infection, they are useful in decreasing the severity and duration of the illness, but are not effective in preventing the illness from occurring in the first place, like vaccines.
240
when would you get an antiviral meidicne
Some people with compromised immune systems, such as the elderly or those with cancer or HIV, might not be able to fight a viral infection on their own. Antiviral medicines can decrease the severity and shorten the duration of the illness, preventing further complications.
241
what are the ways antiviral medications work
blocking the virus from entering the cell
interfering with the replication of the virus
interfering with the release of the newly formed viruses
242
Blocking the virus from entering the cell
drugs can mimic the virus and prevent the actual virus from binding
Drugs that interfere with the ability of the viral genetic material to enter the host cell (via a more permable cell membrane) are effective at preventing the virus from reproducing.
243
Interfering with the replication of the virus
The virus uses the host cell's machinery to reproduce, so some antiviral medicines can interfere with this process, producing incomplete viruses. Some drugs introduce inactive genetic building blocks into infected host cells. When used to make new viruses, inactivated genetic building blocks then produce viruses which are ineffective. Other medicines interfere with the host's ability to generate the protein capsule for the virus, so that the newly made viruses do not have the structure and protection of that outer capsule.
244
Interfering with the release of the newly-formed viruses
Once the assembled viruses are ready to be released, the host cell must activate certain proteins to allow the viruses out. Drugs can be used to block the action of these 'release molecules'. The newly made viruses are then trapped inside the host cell and are not able to be released to infect other healthy cells.
245
flu symptoms
headache (central)
runny stuffy nose
sore throat
fever
coughing
vomiting
aches
246
what antiviral medicine have been used for the treatment of severe influenza
oseltamivir or tamiflu
zanamivir or relenza
247
what functional groups do the antiviral medicines have been used for the treatment of severe influenza
carboxamide group, amino group,
ether group
248
what functional groups do the antiviral medicines have been used for the treatment of severe influenza (oseltamivir and zanamivir)
carboxamide group, amino group,
ether group
carbon carbon double bond
249
why is zanamivir more soluble than oseltamivir
it has a carboxyl group and multiple hydroxyl groups
250
how do oseltamivir and zanamivir work
by blocking the exit of the newly-made viruses from the host cell. In order for the virus to leave the host cell, an enzyme on the virus, called neuraminidase, cuts through the host's cell membrane. When this occurs, the newly-made viruses go on to attack other cells and the host cell is left with a hole in the membrane, which generally means death for the cell. Oseltamivir and zanamivir are referred to as neuraminidase inhibitors, since they both work to inactivate neuraminidase, so the virus is not able to leave or detach itself from the host cell.
251
when must antivirals for influenza be taken
within the first 48 hours of the onset of symptoms
252
who is oseltamivir recommended for
Post-infection: any age
Prophylactic: 3 months and over
253
what is aprophylatic
Antivirals have also been used as a prophylactic (to prevent contracting influenza) in individuals that have come in close contact with an infected person.
254
who is Zanamivir recommended for
Post-infection: 7 years and over
Prophylactic: 5 years and over
NOT FOR
Individuals with respiratory problems (e.g. asthma) or milk allergy
255
how is oseltamivir taken
oral tablet
256
how is zanamivir taken
oral inhalation
257
two methods of mutation for viruses
antigenic drift
antigenic shift
258
what is antigenic drift
where small mistakes are made in the reproduction process, resulting in changes to the proteins on the outside of the virus, making a new strain. When this occurs, the immune system does not recognise the virus any more and it can infect host cells, even if immunity to a different strain of the virus had already been established.
259
what is antigenic shift
where two or more different strains of the virus infect the same cell, producing a new hybrid strain. The hybrid strain now contains a combination of different proteins on the outside of the virus, which the immune system is not able to recognise and fight.
260
what does the HIV do
attacks the cells that make up the body's immune system. If left untreated, HIV develops into acquired immune deficiency syndrome, or AIDS.
261
symptoms of HIV
fever
weight loss
headache
rash
sores
myalgia
nausea
vomiting
262
how is hiv transmitted
HIV can only be transmitted by certain bodily fluids, such as blood, breast milk, vaginal fluids or semen, where the virus is in higher concentration. It can be spread during sexual contact with an infected person, by sharing unsterilised needles or other surgical equipment, by receiving a blood transfusion with infected blood products or from mother to baby during pregnancy or breastfeeding.
263
what does HIV attack
a type of T-cells that contain a CD4 antigen (sometimes called CD4 cells) to reproduce and make more viruses.
264
what are CD4 cells
CD4 cells, like all T-cells, are part of the body's immune response, so the problem with an HIV infection is that over time, the CD4 cells that are involved in producing more viruses are killed when the CD4 cell bursts open, releasing the newly-made viruses. Depleting the body's immune system response weakens it, leaving the body susceptible to any form of infection. In time, when nearly all the CD4 cells are gone, the patient would be diagnosed with AIDS and even a common cold virus could result in death.
265
what is a retrovirus
a special type of virus that contains slightly different genetic material than a traditional virus (it contains a single strand of RNA compared to a double strand of DNA in a traditional virus).
266
is hiv a retrovirus or antiretrovirus
retrovirus
267
what are antiretroviruses
The replication of the virus includes an additional step of converting RNA to DNA, so this makes the virus more prone to mutation (mistakes in the genetic code). Mutations can result in a virus that is constantly changing so much that the medicines designed to combat it are ineffective
268
why do most patients on antiretroviral treatment (ART) take a 'cocktail', or mixture of different antiretroviral drugs
to target the different stages of the retrovirus life cycle. This helps to ensure that the virus life cycle can be more effectively stopped. Taking ART can be very effective at reducing the patient's viral load, the concentration of virus in a blood sample, to undetectable levels in the blood, ensuring a longer, healthier life and reducing the risk of transmission to other people.
269
why is it difficult to develop an HIV vaccine
due to many factors. It would be unwise to use a heat-killed virus, as some vaccines use, because of the risk that not all of the viruses were killed and the vaccine could actually cause HIV infection. Many vaccine studies start with animal studies, but HIV does not affect animals the same way as humans, so the clinical trial process is challenging. Finding human test subjects is difficult because it would be unethical to knowingly infect a person with HIV to test the effectiveness of the vaccine. Clinical trials in humans would have to involve individuals who are at a high risk of contracting HIV anyway, such as intravenous drug users, workers in the sex trade or the sexual partners of HIV-positive individuals.
Another issue is that HIV is a retrovirus and there are currently no vaccines that have been developed for any retroviruses. Since a retrovirus contains RNA, which is then converted to DNA and incorporated into the host cell's own genetic material, the HIV viral DNA can remain dormant (inactive) in the host cell for years before it begins to produce viruses and the person shows symptoms of the illness. Since the virus can remain inactive, the presentation of illness may be delayed and therefore the efficacy of the vaccine may be difficult to measure.
270
In a given reaction to synthesise medicines, the solvent accounts for how much of the initial mass
80-90% (with the reactants only accounting for the other 10-20%)
271
polar solvents
water
alcohol
272
nonpolar solvents
alkanes
benzene
ethers
273
which solvents are less harmful to the environment
polar solvents
274
disposal of polar solvents generally involves
filtration or distillation to remove harmful impurities
275
how to dispose of alcohols
dilute with water or incinerated with a combustion reaction
276
methanol combustion
2 CH3OH (l) + 3 O2 (g) → 2 CO2 (g) + 4 H2O (g)
277
ethanol combustion
CH3CH2OH (l) + 3 O2 (g) → 2 CO2 (g) + 3 H2O (g)
278
problem with disposing of benzene
often carcinogenic. can inhibit photosynthesis
279
problem with disposing of hexane
a neurotoxin that can cause numbness and weakness in the arms and legs and stunted growth in plants.
280
problems with disposing of ethers
can cause dizziness, leading to unconsciousness, in humans and animals and can lead to severe dehydration in plants.
281
why is antibiotic disposal a problem
often people stop taking medicine when they feel better
the drugs will still have some medicinal effect
282
why is antibiotic disposal a problem
often people stop taking medicine when they feel better
the drugs will still have some medicinal effect
lots of agricultural animals are injected with antibiotics
283
example of antibiotic resistance
causes bacteria to adapt by increasing the production of compounds, like penicillinase, that destroy the beta-lactam ring, rendering the antibiotic useless. These bacteria then reproduce, making further generations of antibiotic-resistant strains that become difficult to control. This can lead to the formation of a superbug, a strain of bacteria that is resistant to many antibiotics.
284
how is mediicnal waste disposed of
incinerated on site at hospitals or pharmaceutical companies, but dangerous compounds, such as dioxins, can be generated in this process. The harmful byproducts of incineration must then be filtered and collected as solid waste, which must then be disposed of carefully to ensure that these substances do not end up in the environment.
285
what are nuclear medicines
involve the use of radioactive substances to diagnose and to treat certain diseases, such as cancer. Radioactive isotopes that are ingested or injected into a patient can enhance medical imaging techniques to better diagnose broken bones, the presence of tumours, the risk for heart attack or the functioning of specific organs.
286
what produces nuclear waste
unused samples of radioisotopes and also from any materials or equipment that have come in contact with the radioisotopes.
287
what type of radiation does nuclear medicine generate
gamma radiation
288
dangers of gamma radiation
causes damage at the cellular level, specifically damage to DNA. These changes result in cell damage, uncontrolled cell growth, or cell death. There are sources of naturally occurring isotopes that release gamma radiation that you come in contact with regularly, but at such low levels that the degree of cell damage is undetectable or the cell is able to repair the damage. The risks of serious health effects from gamma radiation depend on the level of the dose that is absorbed by the body in a given time period.
289
radiation sickness occurs when
exposure to significant gamma radiation. which can occur from drinking contaminated water, eating fruits or vegetables grown in contaminated water or even just by being in close proximity to a source of radioactive isotopes.
290
low dose exposure to gamma radiation can result in...
skin rashes, nausea, diarrhoea and vomiting.
291
high dose exposure to gamma radiation can result in
cancer, decreased fertility or death.
292
treatment for radiation sickness
antibiotics, blood transfusions and even stem cell transplants.
293
what is a geiger counter
measures radiation emitted by objects
294
categories of nuclear waste
high level waste
low level waste
295
high level radiation waste
contains a greater radioactive content and is typically produced from spent uranium fuel from nuclear reactors and other liquid waste that comes in contact with the fuel.
296
low level radiation waste
contains less radioactive content and typically includes protective clothing, tools and cleaning materials used at nuclear power generating stations and also the nuclear medical waste generated from hospitals, which includes patient linens, used syringes and empty vials
297
how is HLW transported
generates a lot of heat during the radioactive decay process and is typically stored in large pools of water, called wet storage, until the level of radiation is low enough that it can be safely transported and stored in steel cylinders, dry storage.
298
how is LLW transported
safe enough that it can be transported to a central storage facility and stored in dry storage. The steel cylinders in dry storage can be buried and encased in concrete or additional steel to limit the amount of radiation emitted. The steel cylinders must be resistant to corrosion, to avoid leaks, and are also welded shut.
299
what is green chemistry
aims to reduce waste and energy to produce safer compounds and to limit the use and production of dangerous or harmful compounds in the process. The principles of green chemistry vary from country to country, but the basic concepts are still the same
300
green chemistry pricniples
waste prevention
atom economy
less hazardous chemical design and synthesis
safer and restricted use of solvents
energy efficency
design for degradation
301
what is Design for degradation
Compounds that are generated should be designed to break down into harmless compounds at the end of their function and not remain in the environment.
302
how is carbon dioxide waste managed
can be treated or recaptured to limit its release into the atmosphere.
303
why are chlorinated hydrocarbonds (CFC's) dangerous to the environment
due to the production of free radicals that can destroy ozone molecules, so these compounds have been banned or controlled in many countries and alternative compounds used when available.
304
how is solvent waste recucled
sing fraction distillation equipment. Fraction distillation works by heating up the leftover solvent mixtures and separating the components (fractions) by boiling points. The pure fractions of the mixture are then collected, and solvents can be recycled and any other fractions can be discarded.
305
is recovering solvents worth it
intial cost to the company in the purchase of the equipment, but they save money later on since the companies do not have to purchase as much solvent in the future.
306
what is biodegradation
when some solvents, such as benzene and its derivatives, can be incinerated in a combustion reaction or, when diluted with water, can be decomposed by bacteria
307
is biodegradation vost effective
This process produces the same products as with incineration, but with a lower energy cost since heat is not required to burn the solvent. Biodegradation is also considered to be a more green process, since carbon dioxide gas is being released at a much slower rate than incineration.
308
where might precursors for the synthesis of drugs be found
plants
309
what is the precursor in the antiviral drug oseltamivir, (known by the trade name Tamiflu)
the precursor is found naturally in certain plants, such as the sweetgum plant, certain pine needles and also from the Illicium verum plant, commonly known as Chinese star anise. The precursor, shikimic acid, is present in concentrations of 3-7% in the star anise seeds
310
what can produce shikimic acid
Escherichia coli
311
example of green chemistry
the use of Escherichia coli to produce shikimic acid to produce oseltamivir or tamiflu
312
what does Escherichia coli require
a source of carbohydrates (sugar) and a controlled temperature condition that is close to room temperature, so the reaction conditions are cost- and energy-effective.
313
what forms an enantiomer
when a carbon atom is bonded to four different groups due to the presence of a chiral carbon
314
what is an enantiomer
mirror images of the same compound or object
315
are enantiomers superimposable ro nto
non superimposable
316
what are enantiomers also known as
optical or chiral molecules
317
enantiomers have the same...
chemical and physcial properties but differ in their interactions with other chiral compounds.
318
are amino acids chiral
yes
319
since drug receptors are often proteins or enzymes,
many drug interactions require the interaction with a specific enantiomer.
320
what is a polarimeter used for
to identify which enantiomer is present in a sample
321
what is a racemic mixture
a mixture containing an equal proportion of both enantiomers
322
does racemic mixture contain any optical rotation
no none
323
what happens when a typical reaction produces both enantiomers in equal amounts
a racemic mixture forms and the two enantiomers would then have to be separated and the incorrect one discarded, leading to greater waste production, higher costs and lower yields
324
why must drugs with a chiral centre have steps in the drug synthesis process to be sure the correct enantiomer is made
to ensure the safety of the product and also to promote the production of a higher yield of the correct enantiomer, saving time, money and chemical waste
325
what are chiral auxiliaries
compoundx that contain a chiral centre which are inserted during the drug synthesis phase to promote the production of the correct enantiomer. The chiral auxiliary can then be removed at a later step in the drug synthesis after the specific chiral centre in the drug is made.
326
example of chiral auxiliaries
oxazolidinones. These compounds contain a chiral carbon in the ring structure and are made from amino acids, which are also chiral.
327
the use of chiral auxiliaries promote the formation of the desired enantiomer, but
it can take more time since there are more steps involved in the synthesis of the drug. The benefits of making a single enantiomer, or a considerable portion of one over the other, is more cost-effective overall and in keeping with green chemistry principles. The chiral auxiliary can also be extracted and reused for many synthesis cycles of the drug, adding to the green chemistry practice and helping to reduce the cost of production.
328
what is cancer
uncontrolled growth and division of cells that make a mass or tumour that spreads to other parts of the body, causing more tumours to form
329
cancer treatments
removal of the tumour, treatment with chemotherapy drugs and/or exposure to radiation to decrease the size of the tumour.
330
what is apoptosis
cell suicide
331
what happens when a cell is exposed to chemcials or gamma radiation that cause damage to dna
the cell becomes mutated and can grow out of control. These damaged cells no longer have the necessary checkpoints to be sure that the cell is dividing at the right time or for the right reasons. The cells are damaged beyond the ability for repair and the checkpoint for apoptosis is gone or malfunctions, resulting in the formation of a cancer cell.
332
waht does taxol treat
a variety of cancers including ovarian, lung an dpancreatic
333
what does taxol involve
synthesis with chiral auxilaries
334
side effects of taxol
nausea and vomiting, loss of hair, and tingling in the hands and feet. More serious side effects include female infertility, exhaustion and influenza-like symptoms.
335
taxol was synthesised from trees, but in keeping with green chemistry principles...
taxol is now semi synthesised hemically using a precursor from the needles of the european yew tree which regenerate quickly and do not require the destruction of the entire tree. The precursor is a compound called 10-deacetylbaccatin III and requires eleven steps to synthesise the final drug. Taxol has also been successfully synthesised by biosynthesis using bacteria, plant cell cultures and a fungus that naturally grows on the yew tree.
336
why is nuclear radiation dangerous
its ability to damage cells and cause mutations, can also be used to both diagnose and cure diseases.
337
why is nuclear radiation useful
medical imaging
diagnosing diseases
killing or damaging (cancer) cells
338
what are radioisotopes
unstable atoms that decay to release small subatomic particles and energy which can be useful to enhance medical imaging or to kill cells in a targeted area.
339
what are nuclear reactions
Nuclear reactions involve changes to the nucleus of an atom, that is, changes to the number of protons and/or neutrons. When nuclear changes occur, the amount of energy released is much greater compared to chemical or physical changes to atoms or compounds. The source of nuclear energy comes from the changes in binding energy that hold the protons and neutrons together in the nucleus.
340
what do radioisotopes emit ove rtime
alpha particles (helium nuclei), beta particles (electrons), protons, neutrons or positrons in addition to the gamma ray radiation.
341
alpha
2+ charge
4 relative mass
342
beta
1- charge
0 relative mass
343
proton
1+ charge
1 relative mass
344
neutron
0 charge
1 relative mass
345
positron
1+ charge
0 relative mass
346
gamma
0 charge
0 relative mass
347
compare gamma rays and medical x rays
greater energy, shorter wavelengths and higher frequency
348
what stops alpha
paper
349
what stops beta
skin
350
what stops gamma
cement
351
what stops medical x rays
wood/cement
352
what stops neutrons
not cement
353
why must radioisiotopes used for medical imaging have sufficent gamma radiation
to be emitted from the body and detected by instrumentation
354
why must radioisotopes decay quickly
to ensure that they do not pose a long-term health risk to the patient with excess radiation
355
for radioisotopes with a very short half life,
the patient can be dismissed after the procedure
356
for radioisotopes with a longer half life
the patient must be admitted to the hospital and monitored until enough gamma radiation has decreased before the patient can be released
357
examples of radioisotopes
Tc-99m - medical imaging
Pb-212 - targeted alpha therapy
Y-90 - lymphoma an dliver cancer
Lu-177 - brain and spinal cord tumours
I-131 - medical imaging and treating tumurs in the thyroid
358
Technetium-99m
most commonly used radioisotope. half life 6 hours. synthesised on hospital grounds. gamma decay
359
Technetium-99m decay
99mTc43 → 99Tc43 + γ
360
what must you consider when balancing nuclear equations
both atomic number and atomic mass number on both sides of the reaction arrow. The sum total of the atomic number(s) left of the arrow must equal the sum total of the atomic number(s) on the right. The same rule applies to the atomic mass number.
361
BALANCING
NUCLEAR EQUATIONS
362
what is mri
magnetic resonance imaging. relies on NMR technology.
363
how does mri work
MRI uses a strong magnetic field to influence the protons and neutrons, known collectively as nucleons, in the nuclei of atoms and radio waves to generate images. Atoms with an odd number of nucleons can be detected using MRI. Since 80% of the body's atoms are hydrogen, and 99.98% of hydrogen atoms contain one proton, hydrogen atoms are present throughout the body, generally in water molecules, and these can easily be detected by MRI.
364
hydrogen atoms are aligned in
the presence of a magnetic field
365
stages of mri
magnetic field aligns hydrogen atoms
radio freq waves are then absorbed by the protons and then emitted as a signal
a radio frequency coil picks up the signal and transmits it to the computer
the computer processes the data and an image is generated
366
why can mri be viewed more safely
it uses a magnetic field not gamma radiation but does mean it is not suitable for people that have any ferromagnetic structures (items containing iron, nickel or cobalt) in their body, such as pacemakers (devices that are implanted inside of a person to regulate their heart rate) or artificial joints.
367
when does mri work well
for structures in the body that have a lot of water, since it detects the presence of hydrogen atoms, so MRI scans are used commonly to detect problems in the brain, eyes and soft tissues.
368
when does mri not work well
Bones do not contain a lot of water, so MRI scans are not suitable for images of the skull or bones.
369
nuclear radiation for medical purposes can be appleid
internally or externally
370
External gamma radiation can be applied as a beam to treat ____________
cancerous tumours, often using the radioisotope cobalt-60. Externally applied radiation can also be used in a procedure known as gamma knife radiosurgery, where a series of up to 200 beams can be applied precisely to a target area, such as the brain. Gamma knife radiosurgery does not require the patient to be cut open, so it is less invasive than removing the tumour by traditional surgical methods and the exposure to other healthy tissues is minimised.
371
brachytherapy
short range internal radiotherapy
372
what is brachytherapy
Brachytherapy administers a source of gamma radiation that can be implanted through a wire (catheter) to a targeted area, such as an organ, allowing other healthy tissues to avoid exposure. Some radioisotopes can even be administered by injection with a needle to the target site.
373
how does radiotherapy work
strong beta particle emitting radioisotopes. When cells are exposed to beta particles and gamma radiation, the DNA becomes damaged. Gamma radiation treatment generates the formation of free radicals in cells, which cause cellular damage. Damage from free radicals can be repaired in cells, but since cancer cells divide much faster than healthy cells, they are more likely to already have higher levels of free radicals and mistakes in their genetic material that prevent the cell from being able to repair itself. Healthy cells are better able to repair the damage from gamma radiation, but since cancer cells are already damaged, exposure to gamma radiation can cause irreparable damage and eventually lead to cell death.
374
Luteium-177
Its popularity is due to its relatively short half-life (6.6 days) and the high rate of beta decay
made synthetically during nuclear generation.
375
Luteium-177 equation
177Lu71 → 177Hf72 + 0β-1 + γ
376
yttrium-90
decomposes by beta decay
short half life (64.1 days) so releases gamma rays for a shorter period of time. The zirconium-90 produced in the reaction is also very stable and non-radioactive, so it will not release gamma rays.
produced by beta decay of strontium-90 which is generated during the fission of uranium at nuclear power stations. The yttrium-90 can then be separated from strontium-90 to be used in radiotherapy.
377
yttrium-90 equations
235U92 + 1n0 → 144Xe54 + 90Sr38 + 2 1n0
90Sr38 → 90Y39 + 0β-1 + γ
378
rissks of chemo or radiotherapy
radiotherapy can also damage or kill healthy cells, leading to side effects as cells no longer perform their normal cellular functions
damages dna
379
risks of chemo or radiotherapy
radiotherapy can also damage or kill healthy cells, leading to side effects as cells no longer perform their normal cellular functions
damages dna so rapidly regenerating cells are most at risk eg digestive tract, hair and skin, egg and sperm cells. therefore hair and skin cells lost.
380
minor side effects of radiotherapy
Skin irritation or hair loss at the site of applied radiation.
Fatigue.
Loss of appetite or nausea.
381
seriosus side effects of radiotherapy
Diarrhoea or other digestive upset.
Urinary or other bladder changes.
Sterility (loss of fertility).
Memory loss.
Formation of new cancer due to exposure to gamma rays damaging healthy cells, making them cancerous.
Scar tissue formation, leading to restricted movement.
Reduced immunity, leading to other infections.
382
what does targeted alpha therapy involve
radioisotopes that emit alpha particles
383
why is TAT more effective at killing cells than traditional radiotherapy
the radiation emitted by alpha emitting particles is much more ioninising than beta releasing particles
384
what radioisotope is commonly used in TAT
bismuth-212
385
how does bismuth-212 decay in TAT
by alpha emission
212Bi83 → 4α2 + 208Tl81 + γ
386
describe TAT
involves attaching alpha-emitting particles to an antibody via a small molecule called a chelator, a compound that is capable of forming multiple bonds to a transition metal ion to form a complex ion. An antibody is a special protein that is able to bind specifically to cancer cells that contain a particular antigen, a protein on the cell surface. This ensures that only certain cells are being exposed to the radioisotope, thus 'targeting' the therapy to only cancer cells and not healthy ones. TAT is also being investigated to treat other forms of disease, including HIV-infected cells.
387
what cancers are blood borne and how can you treat them
they are in the blood
eg leukemia or lymphoma. difficult to treat as they exist within the whole body.External or internal radiotherapy would put all healthy cells at risk of exposure to gamma radiation, so TAT provides a better solution because the radioisotope can be injected into the bloodstream, where it can find and locate only those cells with the specific antigen, sparing the healthy cells.
388
what is boron neutron capture therapy
An alternative form of targeted treatment is boron neutron capture therapy (BNCT), which uses a non-radioactive isotope, boron-10, for cancers in the head and neck. `
389
how does boron-10 decay in BNCT
Boron-10 has been observed to effectively capture slow-moving, low-energy neutrons, forming boron-11, which rapidly decays, resulting in the release of an alpha particle
10B5 + 1n0 → 11B5
11B5 → 4α2 + 7Li3 + γ
390
how is BNCT delivered
first administered to the patient by injection and is absorbed by the cancer cells. The boron-10 is attached to a small molecule that is readily absorbed by cancer cells, but not by healthy cells. Then, a beam of neutrons is applied externally. The boron-10 atoms then absorb the neutrons and the reaction occurs, releasing gamma radiation, killing the cell from the inside. Since only those cells that have absorbed the boron-10 can absorb the neutrons and undergo the nuclear reaction, this targeted form of therapy spares healthy cells.
1. boron absorbed by cancer cells
2. neutrons applied as external beam
3. neutron absorption followed by rapid alpha decay occurs in the cancer cells, killing only them.
391
pros of BNCT
effective in treating some cancers that do not respond well to other forms of radiotherapy or chemotherapy, especially those in sensitive areas of the brain that are difficult to access. It is also less invasive, as it only requires an injection to deliver the boron-10 and externally applied neutrons. The neutron beam can cause some skin sensitivity in some patients, but overall less gamma radiation is applied to the patient.
392
calcualting rate of nuclear decay
use a graph: In this decay process, the level of radiation has now been reduced by half. The rate of decay decreases as the concentration of the radioisotope in the sample decreases, so it still takes the same length of time for the concentration to go down by half.
393
why is knowing rate of decay important
for understanding the length of effectiveness of the radioisotope and also the safety risks for the patient and medical professionals. The rate of decay is represented by the half-life of the radioisotope, that is, the length of time for half of the number of atoms (referred to as 'parent' isotopes) to decay, forming the non-radioactive isotope (the 'daughter' isotopes).
394
radioisotopes used for radiotherapy must have
a half life that is long enough to be medically effective but short enough to minimise the amount of excess raditation emitted
395
The symbol t1/2 represents
the halflife
396
λ represents
the rate for a first order decay, measured in units of time-1.
397
when is purification used
when a compound has been isolated from a mixture after an extraction, it must be purified from other substances that might also be present.
398
Extraction methods will isolate and separate based on
polarity but similalr compounds can still be extracted and removed together
399
what does fractional distillation rely on to purify a sample
differences in boiling point (determined by strength of intermolecular forces). substances will boil and separate lowest bp to highest bp.
400
equipment needed for fractional distillation
bunsen burner
round bottom flask
fractionating column
thermometer
condenser
beaker
401
raoult's law
when a volatile liquid is in a closed container, it is in equilibrium with its own gas. The rate of evaporation is equal to the rate of condensation in a dynamic equilibrium. The gas exerts its own vapour pressure in the closed container.
liquid ⇌ gas
402
raoult's law simplified
the vapour pressure of a liquid-liquid mixture is proportional to the individual vapour pressures of the components of the mixture.
403
greater molar mass...
stronger london dispersion forces
404
the combined vapour pressure of both gases is the sum of each indiviual vapour pressure, according to
daltons law of partial pressures
405
explain raoult's law and fractional distillation
both susbtances will exert a vapour pressure and be present in the gaseous phase, in proportion to their individual vapour pressures and mole fractions
406
raoult's law calculation
P =X P^o
A A A
407
waht is Pa in raoults law
the observed vapour pressure of the solvent
408
waht is Xa in raoults law
mole fraction of the solvent in the mixture
409
P^o
A
vapour pressure of the pure solvent.
410
RAOULTS LAW
CALCULATIONS
411
when is spectroscopic methods used
when a chemcial substance needs to be identified or assessed for purity, to ensure it''s the correct substance, identify an uknown compound. infrared, mass and NMR are often used together
412
infrared spectroscopy
uses infrared radiation to bend and stretch covalent bonds, changing the dipole moment of polar bonds. The energy absorbed for the bending and stretching is helpful in identifying the type of bonds present in the molecule, thus identifying particular functional groups for organic molecules.
413
Infrared spectroscopy can identify
carbon-hydrogen bonds and the hydroxyl, ester and carboxyl groups, but not the quantity or placement of these groups in the molecule, so further analysis with mass spectroscopy or NMR would be required to further identify the compound.
414
SPECTROSCOPY
PRACTICE
415
mass spectrometry
analyses a pure compound by charging and accelerating the molecule, causing it to fragment. These fragments are then detected by the mass-to-charge ratio (m/e or m/z), piecing together the different components of the compound. The peak with the highest m/e ratio corresponds to the relative formula mass of the entire compound and the smaller peaks correspond to fragments of the compound. The fragment pattern of the mass spectrum can be very helpful in identifying both the molecular formula for the entire compound and the formula for some of the fragments. The fragment pattern can also be used to identify the compound from a database of known molecules, just like a fingerprint match.
416
what is the most diagnostic method of spectoscopy
1H NMR
417
NMR uses a
strong magnetic field to influence the spin of protons and neutrons inside the nucleus of atoms. For atoms with an odd number of nucleons (protons + neutrons), NMR can influence and detect these atoms, so NMR is commonly used for isotope hydrogen-1, but also sometimes for carbon-13.
418
1H NMR data provides information for
the number of hydrogen environments from the number of peaks, number of hydrogen atoms within each environment from the integration trace, the number of neighbouring hydrogen atoms from the split pattern and also the likely type of bond the hydrogen is involved in from the chemica; shift.
419
how can bac be detected
breathalyser the concentration of alcohol on the breath can be measured and equated to a concentration in the blood in a matter of seconds.`
420
the measurement for concentration of blood alcohol is typically
expressed as a percentage of the mass of ethanol per volume or mass of blood, or by mass of ethanol per litre of breath, if a breathalyser apparatus is used.
421
how does ethanol travel round the body
Ethanol is a toxin that is absorbed through the stomach and travels through the blood to be broken down in the liver and excreted, generally at a rate of about one alcoholic beverage per hour. Some factors, such as gender, age and stress, can influence the rate at which ethanol is detoxified by the liver.
422
The ratio of blood alcohol content to breath alcohol content is about
2100:1, so the mass of ethanol in 1 dm3 of blood is equivalent to the mass of ethanol in 2100 dm3 of expelled breath.
423
how is a redox reaction used to measure concentration of ethanol, based on oxidation of the alcohol
Ethanol in the presence of an oxidising agent, such as potassium dichromate, will undergo oxidation to form ethanoic acid. When this reaction occurs, the dichromate ion, which is orange, undergoes reduction to form chromium sulfate, which is green. The vibrancy of colour is then analysed by a spectrophotometer and equated to the concentration of ethanol in the breath and in the blood.
orange to green
424
what are fuel cells
voltaic (galvanic) cells that produce electricity from a redox reaction. the difference between a typical voltaic cell and a fuel cell is that fuel cells use the oxygen in the air as the fuel source, so they can operate continuously, whereas typical voltaic cells will eventually run out of fuel when the materials undergoing the redox reaction inside the cell (battery) run out.
425
how does redox reactions work in fuel cell breathalysers
When breath containing ethanol passes over the platinum electrodes in the breathalyser apparatus, the platinum oxidises the ethanol to form ethanoic acid and the oxygen in the air is reduced. This reaction generates an electric current that is equated to a blood alcohol content in the breath or blood. Fuel cell breathalysers are more accurate than redox breathalysers, but are more expensive.
426
oral sterioids vs injected steroids
o: convenient, fast acting, clear from body weeks after use
i: more difficult to administer, and remain in the body longer for a prolonged medicinal effect that is more manageable to control but detectable for months later
427
testing for steroids is often done by
mass spectroscopy and chromatoraphy
428
chromatography can detect
components and quantity of a certain component
429
steroid testing chromatography
gas liquid chromatography. The sample is first heated to be vaporised and passed through a long, coiled column, separating the analytes based on boiling point. The analytes travel through the column and are then detected by a sensor when they exit the column. The length of time it takes for the analyte to leave and the relative intensity of the peak of the analyte are both used to determine the identity and quantity of the substance, respectively.
430
GLC: the analaysis produces a peak for each analyte the area under the curve for each peak can be used to give the
relative ratio of the concentration for each analyte in the sample.
431
what is the retention time
the time required for the sample to reach the detector
432
mass spec
used to identify an unknown substance based on its chemical composition. When a substance is analysed by mass spectroscopy, the molecule fragments and the size and ratio of the fragments can be used to identify the substance by comparing it with fragmentation patterns from substances already analysed, like a fingerprint identification.
433
what does analysis from a mass spectrometer produce
mass to charge ratio m/e or m/z
Since all fragments produced during mass spectroscopy have a positive charge from the loss of one or more electrons, all fragments produced are detected by analysis of their mass. The fragment with the largest mass can be used to determine the relative formula mass of the entire compound, which alone can sometimes be used for identification.
434
On a molecular level, drugs interact with the
receptors in cell cytoplasm
receptors in cell membranes
435
What is the angle of rotation of plane-polarised light of a racemic mixture?
A racemic mixture is not optically active and therefore it does not rotate the plane-polarised light passing through it.
436
Zanamivir and Oseltamivir work by inhibiting an enzyme called neuraminidase responsible for:
cutting through the host's cell membrane allowing the replicated virus to leave.
Explanation:
Zanamivir and Oseltamivir inactivate neuraminidase, so the virus is not able to leave or detach itself from the host cell.
437
order of strength of opiates
codeine
morphine
diamorphine
438
Chromatography is a technique used to separate components of a mixture as well as determining the purity of these components. Which piece of information, retention time or peak area, allows you to identify the compound?
The retention time is the time needed for the sample to reach the detector – it is specific for each compound and allows you to identify it by comparing the recorded time with the known retention times.
439
example of a buffer (a solution which resists a change in pH upon addition of a small amount of acid or base)
Ethanoic acid and sodium ethanoate.
Explanation:
Buffer solutions must contain two conjugated species (differing by one H+ ion, in this case CH3COOH / CH3COO-).
440
addiction
characterised by substance seeking and use that is uncontrollable, despite dangerous consequences.
441
Propanone and ethanoic acid are compounds commonly used in organic chemistry. Which statement correctly describes the relationship between the boiling points and vapour pressures of these two pure compounds?
Propanone exerts a greater vapour pressure and has a lower boiling point than ethanoic acid.
Explanation:
Ethanoic acid has hydrogen bonds between its molecules which are stronger intermolecular forces than the dipole-dipole forces that exist between molecules of propanone. At a temperature below its boiling point, these stronger intermolecular forces keep most molecules of ethanoic acid in the liquid phase. Only a few of the molecules evaporate, resulting in a lower vapour pressure. The boiling point of ethanoic acid is higher due to the stronger intermolecular forces.
442
what is green chemsitry
the practice to eliminate and reduce waste while producing safer alternatives to toxic compounds
443
BNCT
10B atoms capture neutrons, forming 11B atoms, which decay rapidly and consequently release alpha particles and gamma radiation.
BNCT is a promising form of radiotherapy for the treatment of head and neck cancers.
444
Zanamivir and Oseltamivir work by inhibiting an enzyme called neuraminidase responsible for:
cutting through the host's cell membrane allowing the replicated virus to leave.
Explanation:
Zanamivir and Oseltamivir inactivate neuraminidase, so the virus is not able to leave or detach itself from the host cell.
445
The purpose of introducing different R groups into the structure of penicillin is to differentiate physical properties of the molecule and therefore its bioavailability. How will the introduction of a non-polar group such as a phenyl group in Penicillin G affect its bioavailability and its administration method?
It will make the molecule less soluble in water and therefore will require delivery by intravenous injection.
Explanation:
The benzene ring in Penicilin G is nonpolar, so it must be injected to have an effect, as it is not water-soluble enough to be absorbed by oral ingestion.
446
What is the difference between the terms opiate and opioid?
Opiates are analgesics derived from natural poppy opium and opioids are synthetically obtained compounds which mimic the behavior of the naturally occurring opiates.
447
How do the opiates work as analgesics?
Opiates bind to endorphin/opioid receptors and interrupt the delivery of the pain signal. Opiates, upon reaching the brain, activate the endorphin/opiate receptors that are found in the brain and produce an effect that mimics the effect of endorphins.
448
What two functional groups are present in the core (backbone) of the three opiates?
Tertiary amine, phenyl (benzene) group.
449
Methadone is used in treating opiate dependence. Name one of the functional groups present in both molecules of methadone and diamorphine.
(tertiary) amine
phenyl
450
Why is codeine less effective as a painkiller than morphine?
Codeine’s ability to bind to receptors is much lower than in morphine.
Codeine must first be metabolised in the liver back into morphine.
451
Diamorphine is a stronger opiate than morphine due to its a higher ability to cross the blood-brain barrier. Why is diamophine able to do this more effectively than morphine?
Because it has the least polar side groups attached to the non-polar core.
452
how to turn morphine into codein
methylation
453
how to turn codeine into morphine
esterification
454
how does ranitidien (zantac) inhibit production of acid in the stomach
by binding to a receptor protein (histamine H2-receptor)
455
which opiate is the least polar
diamorphine contains a non-polar core with not very polar ester groups, while the others have polar hydroxyl groups.
456
Which compounds are responsible for the production of free radicals that destroy ozone molecules in the ozone layer?
chloroflurocarbons
457
what are cfc's
CFCs are organic compounds containing carbon, chlorine, and fluorine atoms. They are non-toxic and non-flammable, but in the presence of UV light produce harmful free radicals, responsible for ozone depletion.
458
why would asprin be chemically modified to a salt
increase its aqueous solbulity
459
State the name given to the process by which solvents, after being diluted with water, are decomposed by bacteria. Answer with one word only.
biodegradation
460
What are the potential effects of nonpolar organic solvents such as hexane or benzene on living organisms?
Hexane is a neurotoxicant and exposure can cause numbness in the feet and hands and later weakness or numbness throughout the arms and legs.
It has been determined that benzene causes cancer in humans and animals.
461
Ethanol is a solvent commonly used in synthesis reactions. What are the proper ways of disposing of leftover ethanol?
incineration of the solvent fora combustion reaction
diluting to a low concentration and disposal as waste water
462
Split-ring commutators swap the connections of a coil every half turn. This means that the
current continues to flow in the same direction.
463
are amino aicds chiral
yes
464
how cna enantiomers be distingusihed from eeahother
using plane polarised light from a polarimeter
465
Each enantiomer will rotate plane polarised light by an equal magnitude,
but in opposite directions.
466
what is a polarimeter sued for
to identify which enantiomer is present in a sample
467
when does a sample have a smaller angle of rotation
where both enantiomers are presnt
468
explain the process by which taxol is isolated
use immisiclble solvents
partitioning of taxol between the two solvents
taxol is more soluble in one solvent
extraction is carried out multiple times
469
outline in breath can be detected by a redox reaction. outline this method of detection. no equation
blow through a tube. acidified orange potassium dichromatee.
Cr2O7 2- reduced to Cr3+
colour change monitored from orange to green
470
describe how fuel cell breathalysers work
ethanol runs over platinum electrodes within the breathalausers
platinum oxidises the ethanol to form ethanoic acid and O2 in the air reduced
471
escribe the differenc in mild vs serious analgesic
mild: prevents the production of prostaglandins
strong: binds to opiod receptors and prevents transmission of pain impulses via neurotransmitters
472
describe how this mixture is seperated by fractional distillation
continuous evaporation and condensation
increased s.a. in column helps condensation
temperature decreases up fractionating column
liquids condense at different heights
liquid of lowest bp collected first/weakest intermoecular forces. most volatile. fractions'liquids colleced in order of bp/volatility
473
how can asprin be made more water soluble
react with NaOH.
474
describe a technique for the detection of steroids in blood and urine
mass spec
databases / library of known fragmentation
oatterns can be used
area under peak proportional to quantity/conc of component present in mixture.
475
explain how the beta lactam ring is responsible for the antibiotic properties of penicillin.
by irreversibilly binding to the enzymes transpeptidase which produces the cell walls of bacteria and this stops cross linkage
476
state a feature of taxol that is major challanenge to its syntehsis
numerous chiral carbons
477
explain how the issue fo taxol having lots of chiral carbons was resolved by pharmaceutical companies
biosynthesis/gen mod bacteria
chiral auxilaries
478
Suggest why the percentage of tecnetium 99m remaining in the human body two days after injection will be lower than the calculated valur
Removed by excretion
479
Explain how TAT is relatively safe to use in the treatment of dispersed can ers
Alpha emitter carried to/selectively absorbed by cancer cells by anitbody.
Low penetrating power,
Short range
480
Outline how chiral auxilaries are used to synthesize the desired enantiomer
Chiral auxilaries create stereochemical conditions necessary to follow a certain pathway.
The chiral molecule/auxilary is added to the starting molecule to force a reaction to follow a certain path.
481
Suggest two reasons why choltinated solvents should neither be released into the atmosphere nor incinerated.
Weak C-Cl bonds produce radicals
Contribute to ozone depletion
Photochemical smog
Cause cancers
Damage respiratory system
Cause organ failure
Produce toxic chemicals
482
Suggest a technique to measure the percentage mass of calcium carbonate in this type of antacid tablet
Back titration. Gravimetric analysis
483
State the equation of calcium carbonate, the active ingredient in some antacids, with stomach acid
CaCO3 + 2HCl --> CaCl2 + H2O + CO2
484
Explain how the beta lactam ring kills bacteria
Binds to the enzyme transpeptidase which prevents bacteria cross linking cell walls
485
sp2 and sp3 bond angles
120 and 109.5
