Chemistry IB SL Exam: Paper 3 Flashcards
How does polarity affect bioavailbility? 3
(a) Describe the differences in the ways that bacteria and viruses multiply. 2
bacteria multiply by cell division/binary fission/mitosis;
viruses insert DNA/RNA/genetic material into cells; 2
For “bacteria multiply by themselves but viruses require a host
cell”/OWTTE award [1].
Define Ionising Radiation: 1-2
Isotopes undergoing the emission of alpha particles, beta particles and gamma particles radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from the orbit of an atom, causing the atom to become charged or ionized.
State the names of two functional groups present in acetaminophen (paracetamol) and one functional group present in ibuprofen. 3
acetaminophen (paracetamol)
acetaminophen (paracetamol):
amide;
hydroxy(l)/phenol/alcohol;
Ibuprofen:
carboxylic acid;
Describe the effect on the individual of consuming depressants at moderate and high doses.
at moderate doses sedation/soothing/reduction of anxiety/impaired judgement;
at higher doses induce sleep/unconsciousness / extremely high dose may cause
death/organ failure;
Define Parental Administration: 2
Any injections that has lead any route other than the gut Includes injection, pulmonary and topical route
Describe the colour change that occurs to the acidified dichromate(VI) if ethanol is present in the breath.
orange to green
Fluoxetine hydrochloride (Prozac®) is a common depressant. Depressants have many therapeutic uses.
State three other common depressants.
diazepam/Valium®;
nitrazepam/Mogadon®;
alcohol/ethanol;
Define Lead Optimization:
When chemical structures of drugs are modified to improve on fixating on a specific target
Police use the intoximeter, an infrared spectrophotometer to confirm a roadside breathalyser test. Explain how the amount of ethanol is determined from the infrared spectrum.
peak at 2950 cm–1/ absorption occurs due to C–H bonds in ethanol;
No mark for absorption due to just ethanol, or O–H bond in ethanol (water vapour in breath also contributes).
intensity / height of peak / absorption / amount of transmittance depends
on amount of ethanol / compare absorption to standard / reference/
control sample / sample containing no alcohol;
(ii) State the general names of the two functional groups attached to the benzene ring in a molecule of aspirin. 2
(ii) carboxylic (acid)/alkanoic (acid); ester; 2
Define Diamorphine:
Another term for heroin
The wider the therapeutic window, the safer or dangerous the drug?
safer
(a) Sodium hydrogencarbonate, NaHCO3, and magnesium hydroxide, Mg(OH)2, can both be used as antacids.
(i) Give the equations for the reactions of sodium hydrogencarbonate and magnesium hydroxide with hydrochloric acid.
NaHCO₃ + HCl → NaCl + H₂O + CO₂;
Accept H2CO3 instead of H₂O and CO₂.
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O;
How many more dose do you need of the same same drug administered intraveneously?
4x
Explain the meaning of the terms:
(i) side-effect
an effect produced in addition to the one intended / unwanted/
undesired effect;
Define Mild Analgesics: 2
A substance that alleviates moderate pain It works by inhibiting the production of chemical messengers that causes the sensation of pain, swelling and fever
Define Pulmonary administration of drugs: 2-3
A method of absorbing drugs by administering it to the lungs in forms of gas or volatile liquidsor aerosol/dry powder inhalers The lungs have a very large surface area so absorption of the drug into the blood is very fast and has fats onset action Useful for treatment of asthma
Define Preventing the virus from leaving the host cell:
The virus is stuck within the host cell and is unable to spread
Define Codeine:
A pain reliever, used for moderate pain Found naturally in opium but in smaller proportions
Define Penicillin:
A type of antibiotic medicine that treats different types of infections and diseases.
Define Ranitidine: 2
A drug that helps reduce stomach acid production by inhibiting the production of acid from the parietal cells of the stomach Also named Zantac
Define Psychological Dependence: 2
When the body requires the drug in order to feel good, the drug user craves for the drug if deprived of it for a short time and must get further supplies in order to satisfy their need
Explain why alginates and dimethicone are often included in antacid tablets.
Alginates:
provide a neutralizing layer on top of the stomach contents / to
prevent acid rising up the esophagus / prevents acid reflux/heartburn;
Dimethicone:
as an anti-foaming agent / to prevent flatulence/gas/bloating;
Define Esterification:
The reaction of carboxylic acids to esters using acid and alcohols Alcohol + Acid to make ester
What are advantages for strong analgesics? 4
Describe the different ways in which mild and strong analgesics prevent pain. 4
strong analgesics:
strong analgesics they bond to receptor sites in the brain;
pain signals within brain/spinal cord blocked; 4
Define Dyspepsia:
Indigestion
Define β-Lactam: 1-2
A class of broad-spectrum antibiotics consisting of different types of agents β-lactam antibiotics are a class of broad-spectrum antibiotics, consisting of all antibiotic agents that contain a beta-lactam ring in their molecular structures. This includes penicillin derivatives, cephalosporins, monobactams, and carbapenems.
Define Therapeutic Index: 3
The ratio of the toxic doe to the therapeutic dose it relates the dose of a drug required to produce a desire therapeutic effect Expressed solely in terms of TD₅₀ because LD₅₀ on humans is not possible
Uses of Aspirin
Anticoagulant
Anti-inflammatory
Painkiller
Why is Patient Compliance important?
Otherwise failure to kill all the bacteria in the infection can lead to development of resistance in those bacteria that survive.
Question: 20. (a) Lysergic acid diethylamide (also known as LSD or “acid”) and mescaline are
both mind-altering drugs. State one effect caused by both substances and one effect
caused by LSD or mescaline only. (Specify the substance which causes the effect.) 2
cause changes in visual and sound perception/hallucinations;
LSD may cause a permanent effect of “flashbacks”/effects of LSD
may be experienced a year or more after the last use of the drug/
psychological dependence; 2
OR
mescaline may cause nausea/trembling/liver damage/reduce appetite;
Aspirin and paracetamol (acetaminophen) are mild analgesics.
(i) State one advantage of aspirin and one disadvantage of paracetamol (acetaminophen).
Advantage of aspirin:
prevents (recurrence of) heart attack/stroke / anticoagulant / reduces
fever/inflammation;
Do not accept increased toxicity when consumed with ethanol.
Do not accept the same argument for advantage of aspirin and
disadvantage of paracetamol.
Do not accept answers which refer to disease (i.e. reduces heart
disease, causes kidney disease) or cancer.
Penalize additional incorrect answers if more than one advantage
or disadvantage is stated.
Define Phase II: 3
Clinical trials where the drug is tested on a small number of volunteer patients who have the disease or the condition that the drug intends on healing This stage establishes whether or not the drug is effective in these patients and also identifies any side effects If the drug is deemed safe and effective, the drug enters Phase 3
Strong analgesic are given for? 3
Question: 1. (a) Many drugs are taken orally. State three other ways in which drugs may be taken by a patient. 2
Answer: 1. (a) rectally/by suppository, by inhalation, by injection (parenterally), by applying to skin/topically; 2
(b) A modern method for accurately determining the amount of ethanol in breath uses an
intoximeter. Describe how an intoximeter works. 3
sample of breath passed into infrared spectrometer;
ethanol in breath absorbs because of C-H bond;
compares breath with air/reference sample with no ethanol; 3
Identify the method of administration used to treat respiratory diseases such as asthma.
inhalation/breathing it in;
Define Physical Dependence:
When the body cannot function without the drug so the user must keep taking the drug to avoid withdrawal effects
Why are viruses considered non-living? 2
What are the sub levels of low level radioactive waste?
A, B, C, and >C
Outline what is meant by the term synergistic effect of ethanol using a suitable example.
ethanol can interact with / enhance the effect of other drugs;
with aspirin increased bleeding of the stomach lining/peptic ulcers or
other suitable example and their effect, such as sedatives, tranquilisers;
Aspiri is a strong or mild analgesic?
mild
One problem associated with ethanol consumption is an increased risk of traffic accidents. Police in many countries use a breathalyser to test drivers. The breathalyser contains potassium dichromate(VI).
Describe the colour change of potassium dichromate(VI) when it reacts with ethanol.
orange to green;
Why cant we use strong bases for antacids?
They are harmful for the body
Define Morphine:
A pain reliver, used for moderate to severe pain Accounts for 10% of the opium mixture
Talk about cultural factors as a sociocultural problem.
Explain why effective treatment of AIDS with antiviral drugs is difficult. 2
HIV virus mutates rapidly;
HIV metabolism linked to that of host cell/HIV uses host cell;
Drugs harm host cell as well as HIV/difficult to target HIV without damaging host cell; 2
What do alginates do?
Suggest why compounds such as sodium hydroxide or potassium hydroxide cannot be used as an antacid.
strong base / corrosive / harmful to the body;
Identify one other effect of a drug which must be determined during clinical trials.
LD50 / ED50;
Or
risk:benefit ratio;
Or
side-effects;
Or
tolerance;
what is the beta lactam ring in penicillums composed of?
Mild analgesics such as aspirin, and strong analgesics such as opiates, differ not only in their potency but also in the ways they act on the central nervous system.
(a) Describe how mild and strong analgesics provide pain relief.
Mild analgesics:
suppress the production of prostaglandins/pain-sensitizing substances /
intercept the pain stimulus at the source
Define Chemical Modification:
The act of having protein reacting with a chemical reagent
What is side effects of taking an opiate analgesic? 2
State with a reason whether chromium in potassium dichromate(VI) is oxidised or reduced by ethanol.
reduced because oxidation number of Cr decreases / Cr gains electrons;
Explanation needed for mark.
What are the reasons for making a drug in a different form to that of the active metabolite?
To avoid side effects To allow the drug to pass through cell membranes – the active form of omezarole is charged and would not pass through the cell membrane into the parietal cells; diamorphine is another drug that fits into this category To allow the drug to dissolve in water more easily — e.g. fosphenytoin To target drugs to a particular area – for example, omeprazole again, where the active drug is formed only in the highly acidic conditions of the cells in the stomach lining
When medicines are in the blood, what is the solubility property that is important?
aqueous solubility
Two substances commonly used in antacid tablets are magnesium hydroxide and aluminium hydroxide.
(a) State an equation to represent a neutralization reaction with one of the above antacids.
Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O
or
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
Define Carboxyl (Carboxylic Acid):
A functional group that consists of a double bonded oxygen to a hydroxyl group (COOH)
tolerance.
person needs to take ever larger quantities of a drug to gain
the original effect;
What does it mean when two drugs increase each other’s effects when taken together?
synergistic effect
Drugs can be what? 4
Relatively crude preparations, obtained by extracting plant or animal materials Pure compounds isolated from natural sources Semi-synthetic compounds, produced by chemical modifications of pure natural compounds Synthetic compounds
Define Active Metabolites:
The active forms of drugs after they have been processed in the body
Explain why dimethicone is added to some antacids.
as an anti-foaming agent
Or
to prevent problem in (c)
Or
to prevent flatulence;
Suggest a reagent that could be used to convert morphine into diamorphine and state the name of the type of reaction taking place.
ethanoic acid / ethanoic anhydride / ethanoyl chloride;
Accept formula instead of name
diesterification / esterification / condensation;
Morphine with ethanoic acid makes what?
diamorphine
When a drug is given to a patient orally, is the bioavailability 100%?
No
Define Side Effect: 2
An unintended secondary effect of the drug on the body; it is usually an undesirable effect. For example, morphine is a strOng analgesic used to treat pain, but I some patients it can cause constipation, nausea and vomiting
Define high level waste?
Has a high activity (many radioactive nuclei decay each second to produce ionising radiation) and usually contains isotopes with longer half-lives (ionising radiation is given off for a long time)
Define Lead Compounds:
A chemical compound that is likely to be therapeutically useful, however it may need some modifications to fit the suited target
What are antibiotics? 4
What’s the most common side effect of aspirin?
the bleeding of the stomach lining
What are 2 examples of strong analgesics?
Morphine and codeine
Is the bioavaility of zanamivir affected if injested orally?
no
Explain how a strong analgesic such as morphine prevents pain. 2
(temporarily) bond to receptor sites in the brain/CNS;
prevent the transmission of pain impulses;
Define Methoxyl:
A radical used in medicinal chemistry, analogous to hydroxyl
Question: 2. One common type of drug taken orally is the antacid. Antacids such as sodium hydrogencarbonate are taken to reduce stomach acidity. (i) State the names of two metals, other than sodium, whose compounds are often used in antacids. 1
magnesium/Mg, aluminium/Al, calcium/Ca; 1
Compare the effectiveness of 1.00 g of sodium hydrogencarbonate to 0.50 g of magnesium hydroxide in combating acidity in the stomach. 3
n(NaHCO₃) = 1.19 × 10–2 mol;
n(Mg(OH)₂) = 8.57 × 10–3 mol;
Mg(OH)₂ reacts with twice the number of moles of acid / is
more effective than NaHCO₃ / OWTTE;
Explain why anti-foaming agents are added and state one example. 2
prevent flatulence/(stomach) bloating / OWTTE;
dimethicone / polydimethylsiloxane/PDMS;
Define Tolerance:
When the body becomes less responsive to the effects of a drug, and so larger and larger does or need to produce the same effect
Who discovered penicillum?
What are examples of depressants that people become dependent on? 3
Diazepam (Valium) nitrazepam (Mogadon) alcohol
What are antacids? 4
Define Tolerance: 1-3
When the body becomes less responsive to the effects of a drug, and so larger and larger does or need to produce the same effect May develop for two reasons: repeated use of the drug stimulates increased metabolism of the drug – the body is able to prepare the drug more quickly for excretion so that lower levels remain in the body to cause an effect. Or The body may adapt so that it offsets the effects of the drug – for example, by desensitising the target receptors with which the drug binds so that it is not able to produce its effect
Define T-Cells:
A type of white blood cells that circulates our bodies, looking for any threats (infections) Our immune system
Medicines and drugs alter the physiological state of the body including consciousness and coordination.
(a) State one other effect of medicines and drugs on the body.
alters incoming sensory sensations / alters mood or emotions;
What is the systematic name of aspirin?
2-ethanoyloxybenzenecarboxylic acid
Suggest why it is advisable not to drink alcohol when taking other drugs. 2
Any two of the following:
alcohol has a synergistic effect with other drugs;
alcohol depresses central nervous system which alters the effect of other drugs;
increased risk of stomach bleeding with aspirin;
Define Therapeutic:
The treatment of a disease
Define Strong Analgesics: 2
A substance that alleviates extreme/strong pain It works by temporarily binding to opioid receptors in the brain, which blocks the transmission of pain signals to the brain without depressing the central nervous system
he structures of the strong analgesics morphine and heroin (diamorphine) can be found in Table 20 of the Data Booklet.
(i) Identify the amine functional group in the morphine molecule below by drawing a ring around it.
any circle around the nitrogen atom / the nitrogen atom and its three
neighbouring atoms;
What are usuable solvents? 5
Define Analgesics:
Drugs that reduce pain
Define Medicine:
A substance that treats, prevents or alleviates the symptoms of disease
Morphine is a strong analgesic which is administered parenterally.
(i) State the meaning of the term parenteral.
administered by injection;
Define Codeine: 2
A pain reliever, used for moderate pain It is because it is converted into morphine in the body
Define Addiction/Dependence:
The reliance on a substance or drug
Question: 18. (a) State the name of the class of drugs with effects similar to that of adrenaline.
amphetamines/stimulants;
Define Intramuscular Injections: 2
A form of injection that is administered into skeletal muscle (arm, thigh, etc.) Can make the drug injected sustained release if drug is dissolved or suspended in oil
How are antibiotics released into the environment? 3
contrast the different groups in zanamivir and oseltamivir 5
Define Alkaloids:
A class of nitrogenous organic compounds that can affect humans
State the differences between the structures of morphine and diamorphine (heroin). State the names of all functional groups in the molecule of morphine.
Differences:
(two) hydroxy(l)/alcohol and phenol groups are esterified/replaced with
ester/ethanoate/ acet(yl)oxy groups / OWTTE;
Accept formulas instead of group names.
How long is the research and development of new medicines?
The research and development of new medicines is a long and costly process. It usually takes up to 12 years and costs more than $200 million.
Define Vaccines:
A substance used to provide immunity against diseases
Define Prophylactic:
A medicine or drug used to prevent diseases happening in the first place
What are the 3 Clinical Trials for the new drug?
a. Human Pharmacology – testing on small group of healthy volunteers for safety b. Therapeutic Exploratory – evaluates drug’s efficiency and side effects c. Confirmatory Stage – large-scale testing of drug
What are preferred solvents? 5
What are the principles of green chemistry? 12
Prevent waste
Maximize atom economy
Design less hazardous chemical synthesis
Design safer chemicals and processes
Use safer solvents and reaction conditions
Increase energy efficiency
Use renewable products
Avoid chemical derivatives
Design chemicals and products to degrade after use
Analyze in real time to prevent pollution
Minimize the potential for accidents
Define Gastric Irritation: 2
One of the many side effects of Aspirin, depletes the protective mucous layer. This can lead to peptic ulcers and possibly stomach bleeding in some patients
Define Therapeutic Effect:
A desirable and beneficial effect; it alleviates symptoms or treats a particular disease
Define Receptor:
Proteins found on the surface of cells or inside cells that responds when molecules bind to them
Define Placebo 3
Something that looks like the real medicine but does not contain any active drug It is made from inert substance such as starch They are used in clinical trials on new drugs, it is found that people who take placebo feels better even though tey only contain inactive ingredients
What are the sociacultral 4 factors related to the aids problem
What are the commonly used antacids? 4
What are the commonly used antacids? (3) 4 Metal hydroxides, carbonates and hydrocarbonates Magnesium hydroxide 2HCl(aq) + Mg(OH)₂(aq) ⇨ MgCl₂(aq) + 2H₂O(l) Aluminum hydroxide 3HCl(aq) + Al(OH)₃(aq) ⇨ AlCl₃(aq) + 3H₂O(l) Calcium carbonate HCl(aq) + CaCO₃(aq) ⇨ CaCl₂(aq) + H₂O(l) + CO₂(g) Sodium hydrogencarbonate or sodium bicarbonate HCl(aq) + NaHCO₃(aq) ⇨ H₂CO₃(aq) + NaCl(aq)
Define Topical administration of drugs: 2
Applying drug or a substance to the skin in the form of cream, ointments or lotion Used primarily for local effect such as treating acne, dermatitis or skin infection
Question: 19. Diazepam and nitrazepam are two depressants that are very similar in their structures.
State the name of two different functional groups present in both depressants.
amide/ketone/carbonyl;
(tertiary) amine;
Define Buffer solution 2
A solution that resists changes in pH when samll amounts of acids or alkali are added Consists of two components — a weak acid and a conjugate base
Aspirin, paracetamol (acetaminophen), morphine and diamorphine (heroin) are all pain killers.
Their structures are given in Table 20 of the Data Booklet.
(a) Aspirin is thought to interfere with the production of prostaglandins. Explain how this produces an analgesic effect.
prostaglandins are involved in the transmission of pain impulses
(to the brain) / OWTTE;
Penicillums are also _______ antibiotics
beta lactam antibiotics
Mild analgesics such as aspirin, and strong analgesics such as opiates, differ not only in their potency but also in the ways they act on the central nervous system.
(a) Describe how strong analgesics provide pain relief.
Strong analgesics:
bind to (opioid) receptors in the CNS/central nervous system/brain /
suppress the transmission of pain impulses to the brain / OWTTE;
What are side effects of aspirin?
Gastric Irritation — this can lead to peptic ulcers and possibly stomach bleeding in some patients Hypersensitivity — it can trigger an asthma attack Not recommended for children under 16 — it has been associated with Reye’s syndrome, a potentially fatal condition that affects all organs of the body especially the brain and liver
Define Heartburn:
Acid from the stomach rising up into the esophagus causing a burning sensation
Question: 8. The effect of some drugs used to treat cancer depends on geometrical isomerism. One
successful anti-cancer drug is cisplatin, whose formula is PtCl2(NH3)2. Describe the structure of
cisplatin by referring to the following:
- the meaning of the term geometrical isomerism as applied to cisplatin
- diagrams to show the structure of cisplatin and its geometrical isomer
- the types of bonding in cisplatin.
geometrical isomerism — existence of compounds with the same molecular formula but with atoms/groups
or Cl/NH3 arranged differently in space;
both structures correctly labelled as cis and trans;
covalent bonding/shared pairs of electrons;
dative/coordinate/hydrogen/polar bonding;
Talk about resources/medical factors as a sociocultural problem.
Define Bioavailability: 2
The proportion of an administered drug dose that reaches the general blood circulation to get to the site of action If drug is given out by Intravenous Injection, its bioavailability is 100%
(i) Identify the stimulant responsible for addiction to smoking tobacco. 1
nicotine; 1
Explain how heartburn is caused.
acid from the stomach rises into the esophagus;
Define Neuraminidase: 2
Enzymes that create bonds of neuraminic acids required for influenza virus replication
How do antiviral drugs work? 4
Define Small Amounts:
A small quantity of something
Talk about condom use as a sociocultural problem.
What is bioavailability?
What are factoirs that affect the bioavalability? 3
State the name of the type of chemical reaction which is used to convert morphine into diamorphine.
(di)esterification / condensation / (di)acetylation;
The walls of the human stomach contain cells that produce gastric juices. Sodium hydrogencarbonate is an antacid often used to neutralize excess acid.
(a) State an equation for the reaction of stomach acid with this antacid.
NaHCO₃ + HCl → NaCl + H₂O + CO₂ / HCO₃⁻ + H⁺ → H₂O + CO₂;
States not required for mark.
how does oseltamivir and zanamivir work? 3
Diamorphine is produced from what reaction with morphine?
esterfication
(ii) Outline what is meant by the term sympathomimetic drug and state two examples
of short-term effects sympathomimetic drugs have on the human body. 3
sympathomimetic drugs mimic the effect of adrenaline;
Any two of the following:
stimulate the sympathetic nervous system; speed up the heart rate;
increase sweat production; increase rate of breathing; 3 max
What are the 5 main ways on administration of drugs?
Oral Rectal Pulmonary Topical Injections
How may tolerance develop? 2
May develop for two reasons: repeated use of the drug stimulates increased metabolism of the drug – the body is able to prepare the drug more quickly for excretion so that lower levels remain in the body to cause an effect. Or The body may adapt so that it offsets the effects of the drug – for example, by desensitising the target receptors with which the drug binds so that it is not able to produce its effect
Does aspirin have a good solubility?
no
The structures of morphine and diamorphine (heroin) are shown in Table 20 of the Data Booklet. State the name of a functional group present in diamorphine (heroin) but not in morphine.
ester;
Define Oral administration of drugs: 3 + (1.5 advantage and 2 disadvantage)
A substance or drug ingested by the mouth Majority of drugs are given by mouth in the form of tablets, capsules, syrups, and suspensions Passes into the stomach and intestines and then absorbed by the bloodstream to d=travel to the site of action An advantage of taking drugs orally is that it is convenient for patients and easy t self-administer. A disadvantage is that the onset of the drug is slow because it has to be first absorbed And some drugs are destroyed by enzymes in the gut
Why is diamorphine more potent than morphine?
amide; 1
Define Salicylic Acids: 1-2
A compound responsible to break down layers of skin Used especially in making pharmaceuticals and dyes, as an antiseptic and disinfectant especially in treating skin diseases,
What is the type of reaction in making Aspirin? 2
ADDITION-ELIMINATION Or Esterfication
What effects do opiates produce?
Describe two short-term effects of smoking tobacco. 2
increased heart rate; increased blood pressure; reduced urine output;
increased concentration/stimulating effect; 2
Disadvantage of paracetamol:
may cause blood disorders/kidney damage /
(overdose can cause serious) liver damage/brain damage/death / does not reduce
inflammation;
Define Subcutaneous Injections: 2
A form of injection that is administered under the skin to give a slow, sustained effect Example: insulin is given out by this method
Define Bacterial Resistance: 2-3
Bacteria resisting the effects given off by drugs Antibiotic resistance occurs when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply, causing more harm.
Define Inhibit the activity of Enzymes:
Manipulation and replicating the job of an enzyme Preventing them from binding to the host cell surface
Define TD₅₀:
The dose required to produce a toxic effect in 50% of the test population (‘TD’ -> Toxic dose)
List the two other methods which can be used to inject drugs into the body.
Intramuscular/intermuscular into muscles
and subcutaneous/into fat;
Allow [1] if all three methods are stated in (i) and (ii) but not
in correct place.
Refer to Table 21 in the Data Booklet when answering this question about analgesics.
(a) Describe the different ways in which mild and strong analgesics prevent pain. 4
mild analgesics:
they prevent/interfere with the production of substances/prostaglandins
that cause pain;
they intercept pain at its source;
Define Drug: 2
Any substance that brings about a change in biological function through its chemical reaction . The change in biological function may be for the better — the treatment of disease – or for the worse — poison that cause toxicity
Using pronciples of green chemistry. state some of the things to mprovethe production of oseltamivir 2
Define Blood Brain Barrier: 2-3
A membrane that separates blood from the brain Esentially a lipid barrier that prevents the entry of potentially toxic substances from the capillaries into the brain Allows small, lipid-soluble molecules across and hinders large, polar molecules
Define Indigestion:
Irritation of the stomach lining caused by excess acid producing pain or discomfort in the upper abdomen and/or nausea
Define Recrystallization: 2
A technique used to purify chemicals and substances By dissolving both impurities and a compound in an appropriate solvent, either the desired compound or impurities can be removed from the solution, leaving the other behind.
What is the first stage of drug development? 2
Is the identification of lead compounds This is done through biological testing of compounds by: isolation from natural sources, chemical synthesis and searching through existing “banks” of compounds already synthesized.
Question: 7. Caffeine and nicotine are two stimulants whose structures are shown in Table 21 of
the Data Booklet.
(a) Describe two similarities in their structures, not including the presence of double bonds,
methyl groups and nitrogen atoms. 2
(a) both contain six-membered ring; five-membered ring; (tertiary) amine group;
N- has methyl group attached; 2 max
Explain how morphine can prevent pain.
morphine (temporarily) bonds to/inhibits receptor sites in the brain
(without depressing central nervous system) / OWTTE;
Define Addition-Elimination:
The reaction that occurs for nucleophilic aromatic substitution
Talk about illegal activities as a sociocultural problem.
Define Reye’s Syndrome:
A condition that causes swelling towards the brain and liver
Define Hydroxyl:
A radical used in medicinal chemistry with the formula OH
Antacid medicines often contain alginates and anti-foaming agents.
(i) Explain briefly how alginates prevent heartburn. 2
neutralizes excess stomach acid / produces neutralizing layer;
prevents acid in stomach from rising / prevents acid reflux;
Define Opioid Receptors: 1-2
A group of inhibiting protein receptors Receptors located in the brain and various organs that bind opiates or opioid substances.
Define Synergism: 2
The interaction of two substances or drugs, when given at the same time, have an effect on the body greater than the sum of their individual effects. Certain drugs can increase the effects of other drugs when given at the same time
Morphine with ethanoic anhydride makes what?
diamorphine
Explain the term racemic mixture.
an equimolar/50:50 mixture of two enantiomers; 1
What makes it hard to design drugs that target viruses than bacteria?
The virus’ lack of cell structure
Define Alter the Genetic Material:
Changing the genetic makeup found within the enzyme of the drug
Calcium carbonate can also neutralize stomach acid. The same amounts (in moles) of sodium hydrogencarbonate and calcium carbonate are available. Deduce which antacid will neutralize the greater amount of acid present in the stomach and explain your reasoning. 2
CaCO3;
1 mol NaHCO3 neutralizes 1 mol HCl and 1 mol CaCO₃ neutralizes
2 mol HCl / CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂;
What are the diffulties associated with AIDS? 5
Explain what is meant by the term tolerance and suggest why this is a particular problem for heroin users.
tolerance: more of the drug needs to be taken to achieve the initial effect / OWTTE;
in order to achieve the desired effect heroin users may reach/exceed the lethal dose / heroin users are more likely to commit crimes to pay for gradually increasing doses of the drug / OWTTE;
Define Hemorrhage:
When blood exits from a damaged blood vessel
(ii) Give an equation for the neutralization of hydrochloric acid in the stomach by sodium hydrogencarbonate. 1
(ii) NaHCO3 + HCl → NaCl + H2O + CO2 (not H2CO3); 1
What are the medecines used to treat viral infections?
What are the 2 assumptions we make with solving buffer solutions?
weak acids partially dissociate — the initial concentration of the acid is aproxiamately equal to the equilibrium concentration of the acid
The salt MA completely dissociates in solution — the initial concentration of the salt is aproxiamately equal to the equilibrium concentrail of the base
What are problems with the production of oseltamivir? 3
Discuss two advantages and two disadvantages of using morphine and other opiates for pain relief.
Advantages:
strong(er) analgesics / relieve acute/extreme pain;
wide therapeutic window / OWTTE;
relieve anxiety / induce relaxation / improve the quality of life;
intravenous/faster distribution of drug;
Disadvantages:
euphoria / lack of self-control / dangerous behaviour;
addiction/dependence / withdrawal symptoms;
tolerance / increased risk of overdose upon prolonged use;
kidney/renal failure;
risks associated with intravenous drug administration;
Accept other side-effects (including drug-specific for different opiates).
Question: 3. (i) State what is meant by the term analgesic. Explain the difference in the mode of action of mild and strong analgesics. 3
(i) a substance that reduces pain; mild analgesics intercept pain at the source/interfere with production of substances that cause pain; strong analgesics bond to receptor sites in the brain/prevent the transmission of pain impulses; 3
Medicines and drugs can influence the functioning of the body.
Discuss the term therapeutic window. Your answer should include its meaning, a quantitative description and an explanation of wide and narrow therapeutic windows.
measure of the relative margin of safety of a drug (for a particular treatment for a
typical population) / measure for safe effective treatment;
/
ratio of the lethal dose (LDSO) to the therapeutic or effective dose (ED50) / the range
of dosage of a drug/its concentration in a bodily system/blood;
Definition of LD50 and ED50 not required for mark.
wide therapeutic window exists for small effective dose and larger lethal dose /
toxicity occurs at much higher concentrations than for successful treatment / a
big difference between effective and lethal dose / drugs with wide therapeutic
window are safer;
narrow therapeutic window requires small doses as lethal dose is not large / OWTTE;
Question: 17. (a) One method for detecting ethanol in breath involves blowing through a tube
containing crystals of potassium dichromate(VI). The ethanol turns the crystals from
orange to green.
Explain what happens to both the dichromate(VI) ion and the ethanol in this reaction. 2
the dichromate(VI) ion is reduced/forms the Cr3+ ion;
the ethanol is oxidized/forms ethanal/ethanoic acid; 2
Modifying the side chains in penicillin will cause them to?
What makes diamorphine special from codiene or morphine?
it has 2 ester groups
Define Dependence:
The reliance on a substance or drug
(b) Identify which antacid neutralizes the greater amount of hydrochloric acid if 0.1 mol of
each antacid is used to neutralize the hydrochloric acid present in the stomach.
Al(OH)3/aluminium hydroxide;
Define Omeprazole/Esomeprazole:
A medication used to treat excessive stomach acid production by binding to proton pumps
Define Euphoria:
A state of feeling great, happiness or exhilaration
(b) Some enantiomers can be prepared by using a chiral auxiliary. Outline how a chiral auxiliary functions and state the advantage it provides. 4
a chiral auxiliary is an optically-active species;
that can be connected to a molecule (to make it optically-active);
when this species is reacted further (then removed) only one enantiomer results;
eliminates the need to carry out the separation of the desired enantiomer from a racemic mixture;
Question: 5. Discuss two arguments for and two arguments against the legalization of cannabis.
Answer: 5. Arguments for: effective for certain named diseases; no more (or less) damaging than other drugs e.g. tobacco, alcohol; personal freedom argument/more taxes/frees police to deal with more serious crimes; Arguments for against: some harmful effects/specified example, e.g. increased risk of lung cancer; many users move on to more damaging/“harder” drugs; Arguments against [2 max]. 4
a) One method for detecting ethanol in breath involves blowing through a tube containing crystals of potassium dichromate(VI). The ethanol turns the crystals from orange to green.
Explain what happens to both the dichromate(VI) ion and the ethanol in this reaction.
the dichromate(VI) ion is reduced / forms the Cr3+ ion;
the ethanol is oxidized/forms ethanal/ethanoic acid;
Question: 9. Many drugs and other biologically important molecules consist of chiral species
whose activity depends upon the enantiomer used. Adrenaline (a hormone that is also used as a
drug) is a chiral molecule.
(a) Identify by means of an asterisk (*) the chiral centre in adrenaline, the structure of which
is given below.
Define Hypersensitivity:
Extreme sensitivity to a drug or substance
(b) Discuss the problems associated with nicotine consumption, distinguishing between
short-term and long-term effects. 6
(b) short-term effects increased heart rate/blood pressure/restriction of blood vessels;
acts as an anti-diuretic/reduction in urine output;
long-term effects increased risk of heart disease/coronary thrombosis;
risk of becoming addicted/physically dependent;
high cost;
(increased risk of) (lung, mouth, throat) cancer;
(increased risk of) bronchitis/emphysema;
reduction in capacity of blood to carry oxygen;
withdrawal symptoms/weight gain (on quitting); 6 max
Other than the phenyl group, state the name of one other functional group that is common to
(i) both paracetamol and morphine.
phenol / alcohol / hydroxyl;
Compare how mild and strong analgesics relieve pain in the body. 2
mild analgesics function by intercepting the pain stimulus at the source /
interfere with the production of substances that cause pain/prostaglandins;
strong analgesics work by bonding to receptor sites in the brain / prevent
the transmission of pain impulses without depressing the central
nervous system;
What are the 2 types of stomach acid inhibitors?
H2 antagonists (H2 blockers) and proton pump inhibitors
Define Anti Blood Clotting Effect:
The effect of prohibiting the coagulation of blood therefore lowering the risk of certain cardiovascular diseases like heart attacks and strokes.
morphine and codeine are from what group?
opiates
therapeutic window
range of a drugs concentration (in blood) between effective/ED₅₀ and toxic
levels/LD₅₀ / (Therapeutic Index) = LD₅₀ / ED₅₀;
Do not accept “difference of drug concentration”.
Analgesics are used to relieve pain in the body. Aspirin and paracetamol (acetaminophen) are both mild analgesics.
(a) Discuss the advantages of using aspirin instead of paracetamol. 2
aspirin useful in preventing the recurrence of heart attacks/strokes / prevents
blood clots;
aspirin reduces fever more effectively/antipyretic;
anti-inflammatory;
paracetamol overdose causes long term damage / easier to overdose on
paracetamol / possible liver damage;
Ethanol, a depressant, is sufficiently volatile to pass into the lungs from the bloodstream.
The roadside breathalyser test uses acidified potassium dichromate(VI) which reacts with any ethanol present in the breath and converts it to ethanoic acid.
State the oxidation half-equations that occur in the breathalyser when ethanol is present in the breath.
Oxidation:
C2H5OH + H2O → CH3COOH + 4H+ + 4e–;
Define Reverse Transcriptase:
An enzyme used to create DNA from RNA templates
How much is the research and development of new medicines?
The research and development of new medicines is a long and costly process. It usually takes up to 12 years and costs more than $200 million.
Define Patient Compliance: 2-3
The degree which a patience follows the correct advice given towards medication The treatment is taken Otherwise failure to kill all the bacteria in the infection can lead to development of resistance in those bacteria that survive.
Define Neuraminidase Inhibitors: 3 How does it work? Example drugs?
A drug/medicine that blocks the neuraminidase enzyme It works by binding to the active site of the enzyme, so that viruses remain anchored to the cell and cannot infect other cells Ex oseltamivir (Tamiflu) and zanamivir (Relenza)
Question: 12. Penicillin G was the first antibiotic used to fight infections. The structure of this
antibiotic is as follows:
(a) Determine the molecular formula of penicillin G.
C16H18O4N2S;
(b) Outline the structural similarities and differences between LSD and mescaline.
(Structures are given in Table 21 of the Data Booklet.) 2
both contain amines/aromatic (benzene) ring;
Question: 15. Caffeine is a stimulant with the following structure.
Determine whether both amine groups in caffeine are primary, secondary or tertiary. 1
tertiary; 1
Define Aspirin:
A pain reliver used to treat mild to moderate pain by being activated in its active form; salicylic acid
Explain why it is dangerous to take aspirin when ethanol has also been consumed.
increased risk of stomach bleeding;
Define Physical Dependence: 2
When the body cannot function without the drug the user must keep taking the drug to avoid withdrawal effects
Define Proton Pump Inhibitors:
A group of drug which are responsible for the reduction of stomach acid
MAny undesirable solvents are VOC’s describe that
Volatile organic compounds
How do H2 antagonists, blockers work? 4
How to increase the solubility of aspirin?
by reacting with aqueos NaOH, forming an ionic salt
Define Opium: 2
A narcotic drug and is used as an analgesic A highly addictive, yellowish-brown drug obtained from the pods of a variety of poppy, from which other drugs, such as morphine, are prepared.
Define Anticoagulant:
A substance that prohibits the coagulation of blood
Explain the use of placebos in clinical trials on humans.
placebo contains none of the compound being tested as a drug;
placebo can “fool” the body into healing itself / OWTTE;
placebo is used as a control to measure the effectiveness of a
drug / OWTTE;
half/some of trial group given placebo and half/some given drug;
patients and administrators should not know who gets a placebo
and who gets a drug / double blind trial;
What is a drawback of LD₅₀: 2
Can result in a deaths of a large number of animals And It does not give info on long term toxicity of a drug or toxicities that are non-lethal — infertility or brain damage
Many drugs are taken orally. State three other ways in which drugs may be taken by a patient.
rectally/suppository;
inhalation;
injection/parenterally/intravenous/subcutaneous/intramuscular;
applying to skin/topically;
State and explain whether 0.1 mol of magnesium hydroxide is more effective or less effective than 0.1 mol of aluminium hydroxide.
less effective and (magnesium hydroxide) 2/0.2 mol OH– ions
available as compared to (aluminium hydroxide) 3/0.3 mol OH–
ions for neutralization / neutralizes 2H+/0.2 mol acid as compared
to 3H+/0.3 mol acid; 1
Do not accept aluminium hydroxide can neutralize more acid.
Define Prostaglandins: 2
A type of fatty acid compounds Can cause a number of physiological effects on the body including the induction of pain, inflammation and fever
Define Peptic Ulcer: 2
Erosion of part of the gut lining, caused by acid penetrating the mucous layer. This can be a serious condition if left untreated because it can cause internal bleeding
Question: 4. Morphine is a naturally occurring analgesic that can be converted into codeine. (i) Calculate the difference in relative formula mass between morphine and codeine. 1
(i) 14/14.03 (ignore units); 1
For treating TB, do you need a lot of medicines?
You need a lot of different types of antibiotics becauee they are very resistant to penicillins
What is used to treat AIDS?
antiretroviral drugs
What are examples of good antacids? 5
Both the medicinal effects of opiates and their addictive properties are caused by binding to the _____ opioid receptors in the brain.
Both the medicinal effects of opiates and their addictive properties are caused by binding to the same opioid receptors in the brain.
Where could alginates be found?
in brands of antacids medication
One common type of medicine taken orally is an antacid. Antacids such as sodium hydrogencarbonate are taken to reduce stomach acidity.
(a) State the names of two metals, other than sodium, whose compounds are often used in antacids.
magnesium
Or
aluminium
Or
calcium;
Any two for [1].
Question: 11. (a) Describe the likely effect of a depressant taken in:
a moderate dose
a moderate dose may induce sedation/reduce anxiety or tension/slower mental
activity/slows CNS/causes drowsiness;
What are factors that must be determined in clinical trials? 3
Define Guanidine Group:
A functional group that is on the side chain of arginine
Define Anti Inflammatory Agent: 2
Agent acting to reduce certain signs of inflammation, as swelling, tenderness, fever, and pain. any anti-inflammatory drug, such as cortisone, aspirin, or ibuprofen
Define Phase III: 3
Clinical trials where the drug is tested on a much larger group of volunteer patients This stage confirms the effectiveness of the drug and compares its performance to existing treatments and placebos If the drug passes, then a marketing authorisation may be obtained by the pharmaceutical company from a relevant regulatory authority — this allows the drug to enter the market to be used on patients in the wider community
How are majority of drugs today made?
Synthesized in a chemistry laboratory
What are the two main components of viruses?
Other than the phenyl group, state the name of one other functional group that is common to both aspirin and diamorphine.
ester;
Define Anion:
A negatively charged ion
Paracetamol (acetaminophen) is generally considered to be safe to use as an analgesic in small doses. Other than the possibility of death, outline the problems associated with taking larger doses of paracetamol. 2 max
causes blood disorders;
causes damage to kidney;
causes damage to liver;
causes damage to brain;
utline the major stages in the development of a new drug. 3
drug is isolated from existing species / synthesized in the laboratory;
tested on animals to establish LD50;
tested on humans and half/some of the group is given a placebo;
State one important use for aspirin other than the relief of pain and fever.
preventing (recurrence of) heart attacks/strokes / reduces blood
clotting / thins the blood / anti-inflammatory;
Tablets of the drug Ecstasy are sometimes contaminated with a substance called 4−MTA.
(i) Ecstasy and 4-MTAare sympathomimetic drugs. Identify the structural similarity
between the two drugs and epinephrine (adrenaline), the structure of which is given
in Table20 of the Data Booklet. 2
all contain the phenylethylamine structure/contain an arene
or benzene ring linked to two carbon atoms attached to an amine group; 1
What are examples of low level waste?
Define Therapeutic Window:
The range of dosage between the minimum required to cause a therapeutic effect and the level which produces unacceptable toxic effects
Discuss two advantages
Advantages:
strong(er) analgesics / relieve acute/extreme pain;
wide therapeutic window / OWTTE;
relieve anxiety / induce relaxation / improve the quality of life;
intravenous/faster distribution of drug;
Identify one functional group present in morphine, but not in diamorphine.
phenol / alcohol / hydroxyl (group);
Allow OH.
(b) Ethanol in breath can be detected using a breathalyser containing potassium
dichromate(VI) crystals. Describe the colour change that occurs in a positive test and
identify the species responsible for the final colour.
orange to green; Cr3+/chromium(III);
What is the Therapeutic index in animals?
LD50/ED50
State what is meant by the term side effect. 1
(b) an effect produced as well as the one intended/unwanted or undesired effect; 1
What is drug? 3 ex
How is zanamivir administered?
inhalation because it has low bioavailability
What makes codeine special from morphine or diamorphine?
It has a 2 ether groups
EX of intermediary level waste?
Define ED₅₀:
The dose required to produce a therapeutic effect in 50% of the test population (‘ED’ -> Effective dose)
iii) placebo effect.
Therapeutic effect of an inert substance on the body / body is fooled into
healing itself naturally /
people responding positively to/psychological effect
after being given a substance that is not a drug / OWTTE;
Explain the meaning of the following terms:
(i) therapeutic window.
the range over which a drug can be safely administered /
ratio of the lethal dose for 50% population and the effective
dose for 50% of population;
What is medicine?
How do proton pump inhibitors work? 4
they inihibit the proton pumps in the stomach
What does modifying the side chain of the penicillin do?
Make it more resistant to the penicillase enzyme
more resistant to stomach acid — which eans the antibiotic can be taken orally
(b) Describe how chiral auxiliaries can be used to synthesize only the desired enantiomeric
form of a drug from a non-chiral starting compound. Explain why it is important to use
only the desired enantiomeric form of a drug and state an example of what can happen if
a racemic mixture is used. 5
a chiral auxiliary is itself an enantiomer;
it is bonded to the reacting molecule to create the stereochemical conditions necessary to follow a certain pathway;
once the desired enantiomer is formed the auxiliary is removed;
different enantiomers may have different biological effects (some of which may be harmful);
genetic defects/deformities;
Define Rectal administration of drugs: 2
A substance or drug being absorbed by the rectal region An advantage of taking drugs by Rectal is that patients can take the drug if they are unconsious or vomiting
The effectiveness of a drug depends on the method of administration.
(i) One method of injecting drugs into the body results in the drug having a very rapid effect. State the method and explain its rapid action.
intravenous / into veins;
transported/pumped via blood (to various parts of body);
Some mild analgesics are derivatives of salicylic acid. The structure of salicylic acid is
Salicylic acid can be converted to aspirin. Give the formula of the group that
replaces one hydrogen atom in a molecule of salicylic acid in this conversion. 1
CH3CO;
Define LD₅₀: 3
The dose required to kill 50% of the animals tested (‘LD’ -> Lethal dose) Expressed in units of mass per kilogram of body weight Can result in a deaths of a large number of animals and It does not give info on long term toxicity of a drug or toxicities that are non-lethal — infertility or brain damage
What is the blood brain barrier? 4
(iii) Explain how heartburn is caused. 1
(iii) acid from the stomach rises into the esophagus; 1
Two examples of mild analgesics are aspirin and paracetamol (acetaminophen). Paracetamol is often used as an alternative to aspirin. State one advantage and one disadvantage of the use of paracetamol.
Advantage:
does not affect stomach/ulceration/bleeding;
or
does not give allergic reactions;
or
does not give Reye’s syndrome;
Disadvantage:
causes blood disorders;
or
causes kidney damage;
or
liver damage;
or
brain damage;
Two examples of mild analgesics are aspirin and paracetamol (acetaminophen). Paracetamol is often used as an alternative to aspirin. State one advantage
Advantage:
does not affect stomach/ulceration/bleeding;
or
does not give allergic reactions;
or
does not give Reye’s syndrome;
Question: 16. Ibuprofen is an analgesic with the following structure:
Identify the chiral carbon atom in the structure of ibuprofen using an asterisk (*). 1
What makes morphine special from codeine or diamorphine?
It has two hydroxyl groups
Define Nucleocapsid:
The capsid of a virus with the enclosed nucleic acid
(iv) Explain why dimethicone is added to some antacids. 1
(iv) as an anti-foaming agent/to prevent problem in (iii)/ to prevent flatulence; 1
(iii) The use of aspirin can have beneficial effects for the user, but can also produce some unwanted side effects. State one beneficial effect (other than its analgesic action) and one unwanted side effect. 2
(iii) Any one of the following [1]. beneficial effects used to treat mini-strokes; prevents heart attacks/reduces risk of heart attack/thins the blood/anti-coagulant; relieves symptoms of rheumatological diseases/anti-inflammatory; reduces fever; 2 Any one of the following [1]. side effects stomach bleeding, allergic reaction; Reye’s syndrome; hearing loss; tinnitus (ringing in the ears); gastrointestinal irritation (e.g. heartburn, nausea); 2
how can the purity of aspirin be determined?
melting point
and
infrared spectrum
Describe one effect, other than relieving depression, of moderate doses of depressants on patients.
sedation/relaxation/soothing/reduction of anxiety/reduces heart rate /
dilates blood vessels / OWTTE;
Accept sleepiness
What are bacterias? 4
Define Psychological Dependence: 2
When the body requires the drug in order to feel good, the user craves for the drug if deprived of it for a short time and must get further supplies in order to satisfy their need.
Define low level waste?
Has a low activity (not many radioactive nuclei decay each second to produce ionising radiation) and usually contains isotopes with short half-lives (ionising radiation is given off for a shorter period of time)
Define Virus Attaches:
The virus attaches itself in order to gain entry of the cell
What is an example of a proton pump inhibitor?
Write an equation for the neutralization of hydrochloric acid in the stomach by sodium hydrogencarbonate.
NaHCO₃ + HCl → NaCl + H₂O + CO₂;
Do not allow H₂CO₃.
Describe two long-term effects of smoking tobacco, other than addiction. 2
increased risk of cancer; increased risk of stroke/(coronary) thrombosis/heart
disease;
ulcers;
emphysema/bronchitis/shortage of breath;
coughing/bad breath/yellowing of teeth or fingers;
effect on pregnancy; 2
Discuss two effects of over prescription of penicillin to humans. 2
makes penicillin less effective;
destroys useful/beneficial bacteria;
allows resistant population to build up; 2
Classify the type of amine present in morphine.
tertiary;
State the names of all functional groups in the molecule of morphine.
Functional groups:
hydroxy(l)/alcohol/phenol;
ether/oxa;
(tertiary) amine/amino;
double bond/alkene;
aromatic/benzene ring/phenyl/aryl;
A modern method for accurately determining the amount of ethanol in breath uses an intoximeter. Describe how an intoximeter works. 3
sample of breath passed into infrared spectrometer;
ethanol in breath absorbs because of C-H bond;
compares breath with air/reference sample with no ethanol
Question: 10. Magnesium hydroxide and aluminium hydroxide can act as antacids.
(a) Write an equation for the reaction of hydrochloric acid with one of the above antacids.
Mg(OH)2 + 2HCl → MgCl2 + 2H2O/Al(OH)3 + 3HCl → AlCl3 + 3H2O;
Define Enzyme:
Biochemical catalysts that catalyse nearly all the chemical reactions that occur in the body
Outline the stages involved in the research, development and testing of new pharmaceutical products. 5
- First the drug must be isolated or synthetized. 2. The drug is tested on animals. LD50 and ED50 are determined. 3. The drug moves to Clinical Trials a. Human Pharmacology – testing on small group of healthy volunteers for safety b. Therapeutic Exploratory – evaluates drug’s efficiency and side effects c. Confirmatory Stage – large-scale testing of drug 4. A local drug regulatory agency approves a medicine and decides whether it will be 5. OTC (over the counter) or on prescription only.
Define Hemagglutinin:
A substance that causes red blood cells to stick together
Define Antacids: 2
Weakly basic compounds used to neutralize acids, relieving pain They are non-specific and do not bind to protein receptors. They work simply by neutralizing excess stomach acid
Define Dosage:
The amount or frequency of a medicine or drug taken
Define Capsid:
The protein coat of DNA and RNA of a virus
Outline two ways in which antiviral drugs work. 2
block enzyme activity within host cell/block reverse transcriptase;
alter host cell’s genetic material;
prevent virus from multiplying/replicating;
alter virus’s binding site on cell wall/prevent virus binding with cell wall;
prevent virus from entering/leaving cell; 2
Why are viruses more harder to treat bacteria? 4
Question: 11. (a) Describe the likely effect of a depressant taken in:
a high dose
a high dose may induce sleep/coma/unconsciousness/death;
What is the Therapeutic index in humans?
TD50/ED50
Define Parasites:
An organism that live in/on another organism stemming nutrients from its host
What type of reaction is codeine produced from morphine? 2
methylation reaction
This reaction makes codeine a less polar molecule than morphine and be able to better cross the blood brain barrier but makes codeine a weaker analgesic than morphine
Do Proton pump inhibitor have longer-lasting effect than antacids?
yes
Define H₂-receptor Antagonist:
A group of medications that block histamine from taking any action
Define Cyclooxygenase:
An enzyme that accountable for the formation of prostanoid compounds including thromboxane and prostaglandins such as prostacyclin.
Example of a H2 inhibitor
Define Phase I: 2
Clinical trials where the drug is tested on a small number, usually fewer than 100, of healthy volunteers Its purpose is to find the dose range of the drug that gives a therapeutic effect and also be able to identify any side effects
State two reasons for modifying the side chain in penicillin G 2
prevents deactivation by stomach acid/more resistant to stomach acid;
prevents deactivation by the enzyme penicillinase (produced by bacteria)/increases resistance/tolerance to penicillinase; 2
What is antibiotioc resistance? 3
Hows does the beta lactam ring work in penicillums? 3
Define Antiviral Drugs:
A class of dugs that fights against viral infections
Discuss two disadvantages of using morphine and other opiates for pain relief.
Disadvantages:
euphoria / lack of self-control / dangerous behaviour;
addiction/dependence / withdrawal symptoms;
tolerance / increased risk of overdose upon prolonged use;
kidney/renal failure;
risks associated with intravenous drug administration;
Accept other side-effects (including drug-specific for different opiates).
How is aspirin made? what is teh reaction?
What are disadvantages for strong analgesics? 4
xamples of strong analgesics are morphine, codeine and diamorphine (heroin). Their structures are shown in Table 20 of the Data Booklet.
(i) Identify two functional groups present in all three of these analgesics.
amine;
ether;
alkene;
benzene ring;
Do not allow arene.
Allow phenyl (ring or group) or benzene.
Allow structural representation of functional group instead of name
(e.g. C=C instead of alkene).
Explain why alginates are often added to antacids.
produce a neutralizing layer/(foam) barrier which prevents heartburn/
acid rising into the esophagus;
What are the effects of Opiates on the body? 4
Analgesia, Sedation, A feeling of well-being And Suppression of the cough complex,
What is the process in which aspirin is purified?
recrystallization
Define Suppositories:
A medical substance that is designed to be inserted into the rectum or vagina
During drug development, trials are conducted to determine the therapeutic window. (a) Explain the meaning of the term therapeutic window and discuss its importance in drug administration. 4
if concentration is too high it will have harmful side effects / determination of the lethal dose (to 50 % of the population) / OWTTE; if concentration is too low it has little or no beneficial effect / determination of the effective dose / dose which has a noticeable effect (on 50 % of the population) / OWTTE; therapeutic window is the range between these doses / range over which a drug can be safely administered / ratio of LD50:ED50; for minor ailments a larger window is desirable, for serious conditions a smaller window may be acceptable / OWTTE; (therapeutic window) depends on the drug/age/sex/weight; a small therapeutic window means that an overdose is a high risk / OWTTE; 4 max
Define Intravenous Injections: 2
A most common form of injection used when a rapid therapeutic response is needed. The drug is injected directly into the bloodstream
Describe the mode of action of penicillin in preventing the growth of bacteria. 2
penicillin interferes with the cell wall formation;
cells can expand/burst/disintegrate/bacteria die; 2
What the main diffrences between bacteria and viruses? 4
Define Semi Synthetic:
A drug or substance that is partially made by synthesis
When medicines are in the brain, what is the solubility property that is important?
lipid solubility
Define Active Drug:
An ingredient found in a drug that is biologically active
What does long term nuse of opiates lead to? 2
dependance and addiction
Define Penicillinase:
An enzyme that can reverse/halt the effects of penicillin by opening the β-Lactam rig of the penicillin.
Two examples of mild analgesics are aspirin and paracetamol (acetaminophen). Paracetamol is often used as an alternative to aspirin. State one disadvantage of the use of paracetamol.
Disadvantage:
causes blood disorders;
or
causes kidney damage;
or
liver damage;
or
brain damage;
Define Methadone:
A similar analgesic, opiate, drug like morphine
When drugs contain basic or acidic properties are turned into salt, does this increaes their solubility?
Yes
(ii) Explain what is meant by developing tolerance towards codeine and state why this is dangerous.
(ii) increasing amounts needed to produce same effect; increasing amounts cause damage/death; 2
State 3 methods of Injections on administration of drugs:
Intravenous, Intramuscular and Subcutaneous
What is an example of green chemistry in action?
(c) Give one reason why sodium hydroxide is not used instead of these antacids.
corrosive to body/tissue/strong base/alkali;
Ethanol, a depressant, is sufficiently volatile to pass into the lungs from the bloodstream.
The roadside breathalyser test uses acidified potassium dichromate(VI) which reacts with any ethanol present in the breath and converts it to ethanoic acid.
State the reduction half-equations that occur in the breathalyser when ethanol is present in the breath.
Reduction:
Cr2O72– + 14H+ + 6e– → 2Cr3+ + 7H2O;
Accept balanced equation with molecular formulas.
If both equations are wrong, award [1] for C2H5OH → CH3COOH
and Cr2O72– → 2Cr3+.
If correct equations are used but oxidation and reduction
reversed, award [1].
Define Placebo Effect:
a beneficial effect, produced by a placebo drug or treatment, that cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient’s belief in that treatment.
Question: 6. Some drug molecules contain a structure that can be represented as follows.
(a) Draw the two enantiomeric forms of this structure.
What are the 2 different categories of Radioactive waste? 2 (+1)
Low level and high level Intermediate level radioactive waste can be used too
State one advantage and one disadvantage of using morphine as a strong analgesic.
Advantage: antidiarrheal/constipation (in treatment of diarrhoea) / reduces coughing;
Disadvantage: addiction / tolerance / risk of overdose;
Dyspepsia, commonly known as indigestion, is due to excess acid in the stomach and can be treated using antacids.
(a) State the name of the acid found in the gastric juices of the stomach.
hydrochloric acid;
placebo effect.
therapeutic effect of an inert substance on the body / body is
fooled into healing itself naturally / OWTTE;
Outline one effect of these drugs on humans.
increased heart rate/increased blood pressure/increased breathing rate
/dilation of pupils/constriction of arteries/sweating/increased alertness
/decreased appetite; 2
Two examples of antacids are aluminium hydroxide and calcium carbonate. State the equations to show the action of each antacid. 2
Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O;
CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O;
Ignore state symbols.
Award [1 max] for correct reactants and products in both equations if
equations are not balanced.
What are penicillins? 2
Are a group of antibiotics used to treat a range of bacterial infections
They are derived fro the penicillum fungi and can be taken orally or by injection
Define Opiates
Natural narcotic (sleep-inducing) analgesics derived from the opium poppy
State the name of the functional group found in heroin but not in morphine.
ester;
State one example of a long-term effect of taking stimulants. 1
weight loss/constipation/emotional instability; 1
What are undesirable solvents?
What are the two main properties that contribute to water solubility of a functional group?
Some antibiotic-resistant bacteria produce a beta-lactamase enzyme which destroys penicillin activity. Suggest how adding clavulanic acid to penicillin enables the antibiotic to retain its activity.
beta-lactam/four-membered ring «in clavulanic acid» reacts with enzyme/beta lactamase
) Populations of antibiotic-resistant bacteria have increased significantly over the
last 60 years. Outline why antibiotics such as penicillin should not be prescribed
to people suffering from a viral infection. [2]
iiantibiotics not effective against virusesORviruses have no cell wall/cell structure/target structures to attack increasing exposure of bacteria «to antibiotic» increases resistance
