Biochemistry Flashcards
1
Q
Define drug
A
A chemical which changes biochemistry
2
Q
Why do most drugs not make covalent bonds with their biomolecular targets?
A
This would require high reactivity which makes it hard to be selective. If covalent chemistry is used in the body it would need to be heated to 80-90 degrees under reflux which is not possible
3
Q
How do electrostatic interactions come about?
A
The attraction between molecules bearing opposite electronic charges
4
Q
How do ion-ion interactions happen?
A
The closer they get the more attraction they feel until a certain point when you get repulsion
5
Q
Why are ion-ion interactions stronger in a hydrophobic environment than a polar environment?
A
Due to competition by water. Usually, binding site is more hydrophobic than the surface, so this increases the effect of an ionic interaction
6
Q
What are hydrogen bonds?
A
Electrostatic interactions between a polarised proton with a nearby atom bearing a lone pair
7
Q
Define amino acid
A
Bifunctional organic compounds that possess both a carbonyl and amino group
8
Q
What is an alpha amino acid?
A
Where the carbonyl and amino group are attached to the same central carbon atom (alpha-carbon atom)
9
Q
Why can amino acids act as nucleophiles?
A
Due to their lone pairs
10
Q
Define a Bronsted-Lowry acid
A
A proton donor
11
Q
Define a Bronsted-Lowry base
A
A proton acceptor
12
Q
How is basicity most commonly measured?
A
Using the pKa of a conjugate acid
13
Q
Finish the sentence: the less acidic the conjugate acid…
A
the more stable it is, the lower the Ka, the higher the pKa, and therefore the more basic the original base
14
Q
What does pKa tell you?
A
The pH at which the molecule is 50% protonated
15
Q
What is the difference between an L-amino acid and a D-amino acid?
A
L-amino acids rotate plane polarised light to the left, and D-amino acids rotate plane polarised light to the right
16
Q
Define amphoteric
A
Can react as either an acid or a base
17
Q
Define isoelectric point (pl)
A
the pH at which the amino acid exists largely in an overall neutral, Zwitterionic form
18
Q
How to calculate the pl for neutral amino acids?
A
The average of the two pKa values
19
Q
How to calculate the pl for acidic amino acids?
A
The average of the two lower pKa values
20
Q
How to calculate the pl for basic amino acids?
A
The average of the two higher pKa values
21
Q
Define peptide
A
Chain of amino acids
22
Q
What does ‘write N-terminus to C-terminus’ mean?
A
The amine group is on the left of the chain and the carboxyl group is on the right of the chain
23
Q
How do amides form?
A
Condensation reaction between amines and carboxylic acids
24
Q
How do we control where a reaction between amino acids occur?
A
Using protecting groups or the automated process which involves beads
25
How do we calculate the isoelectric point for peptides?
1. Write out pKas from highest to lowest
2. Choose a pH below the lowest and calculate the charge
3. Choose a pH between the first and second lowest and calculate the charge
4. Repeat
5. pl is the average of the pKas either side of q=0
26
What is the primary structure of a protein?
The amino acid sequence
27
What are the two main secondary structures?
Alpha helix, beta sheet
28
What are the tertiary and quaternary structure?
Tertiary - multiple alpha helices/beta pleated sheets
Quaternary - multiple tertiary structures
29
What holds alpha helices and beta pleated sheets together?
hydrogen bonds
30
How long does it take to return to the same point in an alpha helix?
Every 7 amino acids
31
What is a beta pleated sheet?
Long, straight chains which stack next to each other and are held together by hydrogen bonding
32
What are the four less common secondary structures?
Beta turn, 310 helix, triple helix, random coil
33
What is the purpose of disulphide bridges in the tertiary structure?
Bring two peptide fragments together
34
What is the process for making protein crystals?
1. Protein in water with non-solvent placed as drop on lid
2. Non-solvent in well/flask
3. Water evaporates from drop
4. Protein crystals form
35
Why is NMR good for determining protein structure?
- More native conditions
- No need for crystallisation
- Less precise conditions
- Less automated
36
Why is cryo-EM good for determining protein structure?
- More native conditions
- No need for crystallisation
- Lower resolution
- Relies on previous models
37
How does gel electrophoresis help determine protein structure?
Mass/charge ratio is used and movement will depend on protein charge (pKa and pl)
38
give examples of globular proteins
antibodies, membrane channels, enzymes
39
give examples of fibrous proteins
collagen, silk
40
what is the difference between globular and fibrous proteins?
fibrous proteins create very long structures which provide structural integrity, whereas globular proteins are individual units and perform more chemical tasks
41
define antigen
a foreign substance that enters the body, such as bacteria, fungi, allergens, venom, and toxins
42
define antibody
a protein produced by your immune system to attack and fight off antigens
43
what are membrane proteins?
proteins that can transport chemicals and information across biological barriers
44
what are enzymes?
the body's catalysts - agents that speed up reactions without being consumed
45
describe the process of an enzyme working
1. substrates enter active site
2. substrates are held in active site by weak interactions, forming an enzyme-substrate complex
3. enzyme can lower activation energy and speed up a reaction
4. substrates are converted to products
5. products are released
6. active site is available for two new substrate molecules
46
what is chymotrypsin?
an enzyme that is used in the small intestine to break down proteins into individual amino acids
47
what is a competitive inhibitor?
they resemble the desired substrate and can be bound to the active site, preventing the desired substrate from binding and a reaction occurring
48
what is a non-competitive inhibitor?
they bind to another place on the enzyme which alters its structure and prevents binding
49
how many hydrogen bonds are between A and T?
two
50
how many hydrogen bonds are between G and C?
3
51
what is deoxyribose?
ribose without the OH group bonded to carbon 2
52
what do the different carbons attach/bond to on deoxyribose to form DNA?
the OH groups on carbons 3 and 5 attach to a phosphate, and the OH group on carbon 1 attaches to the nucleobase
53
define nucleoside
base with sugar attached
54
define nucleotide
base with sugar and phosphate attached
55
why is DNA an antiparallel duplex?
as when going down the DNA strand we go 5' to 3', and when doing up on the other side we go 5' to 3' meaning they are opposites of one another
56
why is DNA with a higher GC content more stable?
as GC has three double bonds compared to AT which has 2
57
define hybridization
the process in which two complementary single-stranded DNA and/or RNA molecules bond together to form a double-stranded molecule
58
How do we find the complementary sequence?
1. split strand into three base units for clarity
2. write down the complementary bases
3. reverse the order to give the strand in 5' to 3' format
59
what does the 'melting temperature' of DNA mean?
when half of the strands are in a random coil single strand state
60
why does DNA have a double helix structure?
the negatively charged phosphate groups repel each other, the presence of hydrogen bonds, and stacking of nucleobases through hydrophobic/Van der Waals interactions compacts the duplex vertically
61
where are quadruple helixes found?
in telomeres at the end of chromosomes
62
how is a triplex formed?
a third strand binds in the major groove
63
what do telomeres do?
determine the lifetime of DNA
64
what is the difference between the molecules of RNA and DNA (not the bases)?
extra OH group
65
what is the structure of a chromosome?
DNA is coiled around proteins called histones to produce nucleosomes, which are further packed to produce chromosomes
66
how many protein units are required for one nucleosome?
8
67
Describe the process of transcription (6 marks)
- DNA helicase binds to a complementary start codon on the DNA and breaks hydrogen bonds
- DNA unwinds forming a template strand
- Each exposed base binds to a complementary, free floating nucleotide
- C with G, A with U
- RNA polymerase moves along the DNA strand, causing the phosphodiester bonds to form between nucleotides
- This forms pre-mRNA which is then spliced to remove the introns so it can fit through nuclear pores
68
Describe the process of translation (4-6 marks)
-mRNA moves out of the nucleus via nuclear pores and attaches to a ribosome
- tRNA carrying amino acids bind their anticodons to the complementary codon on the mRNA
- A second tRNA does the same and the two amino acids form a peptide bond
- The first tRNA molecule moves away
- The process continues and only ends when a stop codon is reached, forming a polypeptide
69
What is are the three stages of the polymerase chain reaction?
1. Separation of the DNA strand - the DNA fragments, primers, and the DNA polymerase are placed in a vessel in the thermocycler at 95 degrees which causes the two strands of DNA fragments to separate due to the breaking of hydrogen bonds
2. Addition (annealing) of the primers - the mixture is cooled to 55 degrees so the primers can join (anneal) to their complementary bases at the end of the DNA fragment, providing starting sequences for DNA polymerase
3. Synthesis of DNA - temperature raised to 72 degrees as this is the optimum temperature for DNA polymerase to add complementary nucleotides along each of the separated DNA strands
70
What is the empirical formula for carbohydrates?
C(H2O)
71
How are hemiacetals formed?
By the reaction of a carbonyl and an alcohol
72
What are glycodies?
Small non-sugar molecules attached through anomeric position to a sugar
73
What are the two distinct parts of a fatty acid?
The long hydrocarbon chain and a carboxylic acid group
74
Is the hydrocarbon chain in a fatty acid hydrophobic and hydrophilic?
Hydrophobic
75
How do fatty acids form esters and amides?
The acid group readily reacts with a hydroxyl or an amino group on a second molecule
76
How do fatty acids differ from one another?
Length of hydrocarbon chain and number and position of the carbon-carbon double bonds
77
What is the difference between saturated and unsaturated?
Saturated has no carbon-carbon double bonds, and unsaturated does
78
What are phospholipids composed of?
Two fatty acids, glycerol, and a phosphodiester head
79
What are steroids?
A class of lipid with a polycyclic aliphatic carbon skeleton
80
What are the two wider roles of cholesterol?
As an intermediate in biosynthesis of other steroids, and in control of membrane fluidity
81
Amphipiles such as phospholipids are subject to two conflicting forces. What are these?
1. The hydrophilic head is attracted to water
2. The hydrophobic tail repels water and seeks to aggregate with other hydrophobic units
82
What are the different proteins in the membrane?
Ion channels, receptors, and transporters
83
Why can individual phospholipids rotate axially or fatty acid tails flex?
Because the VdW interactions are very similar for each arrangement
84
Why is fluidity important in the membrane?
- Processes such as exocytosis, endocytosis, membrane trafficking, and membrane synthesis
- Allows membranes to fuse and molecules to mix
- Allows even distribution of membrane molecules between daughter cells following cell division
85
What are the factors influencing fluidity and why?
Length - shorter, reduced interactions of the hydrocarbon tails so more fluid
Saturation - each double bond in an unsaturated tail creates a small link
Cholesterol - fill the spaces between the neighbouring phospholipid molecules
86
Does fluidity increase or decrease in membranes with increasing cholesterol content?
Decreases
87
Why are cellular membranes asymmetric?
1. Two layers of bilayer have different compositions
2. Different phospholipid/glycolipid inside and outside
3. Membrane proteins embedded into membrane with a specific orientation
4. All lipids are synthesised on the cytosolic surface of the endoplasmic reticulum
5. Lipids in the outer leaflets are transported there by flippases
88
How do local anaesthetics work?
Block the conduction of nerve impulses by affecting the influx of ions through transmembrane channels
89
What is the nucleus composed of?
DNA, proteins, lipid membrane
90
What is the nucleosome?
The basic repeating subunit of chromatin packaged inside the cells nucleus
91
What is chromatin?
A mixture of DNA and proteins that form the chromosomes found in the cells of humans and other higher organisms
92
What is topologically associating domain (TAD)?
DNA within these domains interact with each other more than in other domains
93
What is the purpose of nuclear pores?
They allow proteins in and mRNA and ribosomes out
94
What is the cytoplasm?
A viscous liquid that fills the inside of cells
95
What is the cytoplasm made up of?
Water, ions, small molecules, and proteins
96
What occurs in the cytoplasm?
Metabolism and is the medium for signal transduction
97
What is the purpose of mitochondria?
They generate most of the chemical energy needed to power the cells biochemical reactions
98
What is the composition of DNA?
Lipids, proteins, DNA, RNA, small molecules
99
What is the endoplasmic reticulum made up of?
Lipids, proteins, DNA
100
What roles does the endoplasmic reticulum play?
Calcium storage, protein synthesis, and lipid metabolism
101
What is the purpose of the golgi apparatus?
Helps process and package lipid molecules, especially proteins designed to be exported to the cell
102
What is the golgi apparatus composed of?
Lipids and proteins
103
What is the simple process of the function of the golgi apparatus?
1. Receives proteins from ER in vesicles
2. Applies post-translational modifications to proteins
3. Transports them to internal or external vesicles
104
What is the composition of ribosomes?
RNA and proteins
105
What is the function of ribosomes?
Produce proteins by translating mRNA into polypeptides via tRNA
106
Where are ribosomes found?
Cytoplasm, mitochondria, and rough ER
107
What are endosomes and lysosomes made up of?
Lipid membrane
108
What is the function of endosomes and lysosomes?
- They bud off from the ER and golgi apparatus to transport or excrete proteins
- They bud of from the cell membrane to allow the cell to uptake material from outside (endocytosis)
109
Define metabolism
Chemical processes that occur within an organism to maintain life
110
What are the three major steps of cellular respiration?
Glycolysis, Krebs cycle, Oxidative phosphorylation
111
What is the first stage of glycolysis and what happens during it?
Phosphorylation of glucose to glucose phosphate:
Before it can be split into two, glucose must be made more reactive by the addition of two phosphate molecules. These come from the hydrolysis of two ATP molecules to ADP. This provides the energy to activate glucose and lowers the activation energy for the enzyme controlled reactions that follow. Splitting of the phosphorylated glucose:
Each glucose molecule is split into two 3-carbon molecules known as triose phosphate (each 3-carbon molecule has one phosphate attached). Oxidation of triose phosphate:
Hydrogen is removed from each of the two triose phosphate molecules and transferred to a hydrogen carrier molecule known as NAD to form reduced NAD. The production of ATP:
Enzyme controlled reactions convert each triose phosphate into another 3-carbon molecule called pyruvate. In the process, two molecules of ATP are regenerated from ADP.
112
What is the overall yield of one glucose molecule undergoing glycolysis?
- two molecules of ATP (four produced, but two used up in the initial phosphorylation pf glucose)
- two molecules of reduced NAD
- two molecules of pyruvate
113
Does glycolysis require oxygen?
No - it takes place in the cytoplasm and so does not require oxygen, nor any organelles
114
What happens during the link reaction?
- pyruvate is oxidised to acetate. In this reaction, the 3-carbon pyruvate loses a carbon dioxide molecule and two hydrogens. These are accepted by NAD to form reduced NAD which is later used to produce ATP
- The 2-carbon acetate combines with a molecule called coenzyme A to produce an enzyme called acetylcoenzyme A
115
What is the equation for the link reaction?
pyruvate + NAD + CoA ---> acetyl CoA + reduced NAD + carbon dioxide
116
Where does the Krebs cycle occur?
The matrix of the mitochondria
117
Briefly summarise the events that occur in the Krebs cycle (3 bullet points)
1. The 2-carbon acetylcoenzyme A from the link reaction combines with a 4-carbon molecule to produce a 6-carbon molecule
2. In a series of reactions this 6-carbon molecule loses carbon dioxide and hydrogen to give a 4-carbon molecule and a single molecule of ATP produced as a result of substrate-level phosphorylation
3. The 4-carbon molecule can now combine with a new molecule of acetylcoenzyme A to begin the cycle again
118
What does one glucose molecule produce during the Krebs cycle?
(Pyruvate will be half of this as two pyruvates = one glucose molecule?
- 6 reduced NAD
- 2 reduced FAD
- 2 ATP
- 4 carbon dioxide
119
What are coenzymes?
Coenzymes are NOT enzymes. They are molecules that some enzymes require in order to function.
120
Give three examples of coenzymes and what they do
All of the following carry hydrogen atoms from one molecule to another:
- NAD, which is important throughout respiration
- FAD, which is important in the Krebs cycle
- NADP, which is important in photosynthesis
121
Where does oxidative phosphorylation occur?
In the mitochondria - within the inner folded membrane (cristae) are the enzymes and other proteins involved in oxidative phosphorylation and hence ATP synthesis
122
What does the synthesis of ATP by oxidative phosphorylation involve?
The transfer of electrons down a series of electron carrier molecules which together form the electron transfer chain
123
How does the electron transfer chain work?
- The hydrogen atoms produced during glycolysis and the Krebs cycle combine with the coenzymes NAD and FAD
- The reduced NAD and FAD donate the electrons of the hydrogen atoms they are carrying to the first molecule in the electron transfer chain
- The electrons pass along a chain of electron transfer molecules in a series of oxidation-reduction reactions. As these flow along the chain, the energy they release causes the active transport of protons across the membrane into the inter-membranal space
- The protons accumulate here before diffusing back into the matrix through ATP synthase channels in the inner membrane
- At the end of the chain the electrons combine with these protons and oxygen to form water. Oxygen is therefore the last acceptor of electrons in the chain
124
Define enzyme
A class of protein which acts as a catalyst for a biochemical reaction but is not permanently changed in the reaction
125
How do enzymes work?
They lower the activation energy required for the molecular reaction to take place
126
What are co-factors?
'Helper molecules' that assist in biochemical transformations
127
What are the two classifications of co-factors?
loosely bound (co-enzymes) and tightly bound (prosthetic groups)
128
What are prosthetic groups?
Small inorganic ions, mostly metal ions. Act as activators and/or inhibitors of activity
129
What are co-enzymes?
Small, non-protein molecules that catalyse reactions
130
What is competitive inhibition?
Inhibitor competes reversibly with substrate for the active site
131
What is uncompetitive inhibition?
Inhibitor binds only to the ES complex, leading to EIS intermediates
132
What is non-competitive inhibition?
Inhibitor binds non-covalently to sites other than the active site
133
What is irreversible inhibition?
Irreversible inhibitors form covalent or very tight bonds with functional groups on the active site
134
In non-competitive inhibition, what is the site called where binding occurs?
Allosteric site
135
What are neurotransmitters?
chemicals secreted from the presynaptic membrane
136
what are electrical synapses?
ions flow directly from one neurone to another via gap-junctions called electrical synapses
137
what stimuli causes the gating of ion channels
1. Voltage gated
2. Ligand gated (extracellular ligand)
3. Ligand gated (intracellular ligand)
138
Describe how G-protein-coupled receptors work
1. The ligand binds to the G-protein hosting GDP in the alpha subunit
2. Binding changes the conformation of the G-protein, releasing GDP
3. This creates a pocket which binds GDP
4. Binding of GDP causes another conformational change
5. This results in the alpha subunit departing separately
139
Describe the process of phosphorylation
1. cAMP activates protein kinase A
2. Protein kinase A phosphorylates other specific proteins
3. Phosphorylation changes their conformations and activates them in turn
4. Each step we can have multiple turn overs resulting in huge signal amplification
140
What are the four ways drugs can interact with receptors?
Agonist, antagonist, partial agonist, inverse agonist
141
Define agonist
A ligand that binds to and provokes a signal from a receptor via conformational changes to produce the active state
142
Define antagonist
A ligand that binds to a receptor and induces no signal. Blocks agonist binding, and hinders conformational switch to active state
143
Define partial agonist
Binds and provokes a signal but diminished compared to a full agonist. Binding is suboptimal and conformational switch may not fully engage
144
Define inverse agonist
Removed any base-level activity the receptor had in absence of the ligand
145
What are the two main definitions of a drug?
1. A chemical or substance used to prevent or cure disease
2. A substance which has a physiological effect when introduced to the body
146
What are the benefits of using natural products for drugs?
- All natural products have some kind of biological activity already
- Could be produced by agricultural or biotechnological processes
- Provides access to unusual/diverse structures
147
What are the drawbacks of using natural products for drugs?
- Can be difficult to obtain in high yields
- Total synthesis is challenging
- Compounds are not optimised
- Could be allergens
148
What is phenotypic screening?
Approaches only looking at the final effect of a drug, rather than replying on knowledge/hypotheses of how the drug works
149
What is meant by target-based drug discovery?
This means that a certain biomolecule has been identified as problematic, and a drug will be developed to change its behaviour, with the aim of certain final effect
150
What are the three main steps to fitting a drug to a target and what do they ential?
Docking – calculate where and how well a molecule binds to the target. Often using a large virtual library of compounds which could be synthesised
Binding site mapping – creating a model illustrating what arrangement of intermolecular interactions can be addressed
De novo drug design – ask the computer to generate a molecule which could bind in the chosen site
151
What are the benefits of designed synthetic compounds?
- Synthesis straightforward
- Readily modified at any point to tune properties
- Mechanisms of action usually well understood
152
What are the drawbacks of designed synthetic compounds?
- Limited to molecules which are easily made
- Chirality and largest 3D structures rarer
- Does not work so well on proteins without small molecule binding pockets
153
Define screening
measure each molecule's interaction with the target
154
Define selection
use some affinity measurement to separate binders from non-binders
155
What are the benefits of screening and selection?
- Test millions of molecules at once
- Could uncover unexpected activities
- Exploit molecular biology techniques
- Target any protein with larger molecules
156
What are the drawbacks of screening and selection?
- Might not find any good hits
- Limited to libraries which an easily be made
- Larger molecules may have trouble getting through cell membranes
157
Define in vitro
On isolated cells, tissues, and proteins
158
Define in vivo
On entire organisms
159
Why is in vitro usually preferred for initial tests?
It is cheaper, quicker, less controversial, and can be automated
160
Describe the four phases of clinical trials
Phase 1 - Testing safety in a small group of healthy volunteers
Phase 2 - Small scale test for efficacy
Phase 3 - Large scale test for efficacy
Phase 4 - Follow-up studies are conduced post-approval to monitor response in the wider population
161
Define target-based
A certain biomolecule has been identified as problematic and a drug will be developed to change its behaviour with the aim of a certain final effect
162
What does route of administration of a drug depend on?
- Physical and chemical properties of the drug
- Side of desired action --> localised or generalised
- Effect of digestive juices and first pass metabolism of drug
- Accuracy of dosage required
- Condition of patient
163
What are examples of local routes?
1. Topical - external application of the drug to the surface
2. Deeper tissues - certain deep areas can be approached by a syringe
3. Arterial supply - closed intra arterial injection
164
Define sublingual
Kept under the tongue or crushed and spread over the mouth
165
Give the advantages and disadvantages of sublingual administration of drugs
Advantages - rapid absorption, liver is by passed, unconscious patients
Disadvantages - only lipid and saliva soluble drugs, uncooperative patients, irritate the mucosa
166
Give the advantages and disadvantages of intravenous administration of drugs
Advantages - quick action, desired concentration easily obtained, no hepatic first pass metabolism, unconscious and uncooperative patients
Disadvantages - costly, local irritation, self-medication not possible, action cannot be stopped, aseptic and antiseptic measures must be maintained
167
Give the advantages and disadvantages of oral administration of drugs
Advantages - self-medication possible, large area of absorption, simple procedure, slow action, solid and liquid forms
Disadvantages - irritant and unstoppable drugs cannot be administered, may induce nausea and vomiting, not useful when vomiting and diarrhoea present, not useful when patient is unconscious, can be destroyed by gastric juices
168
What does Lipinksi's Rule of 5 state?
In general an orally active compound has no more than one violation of the following criteria:
- < 5 hydrogen bond donors
- < 10 hydrogen bond acceptors
169
The movement of a drug can be influenced by ADME. What does this stand for?
Absorption
Distribution
Metabolism
Excretion
170
In terms of ADME, define absorption
The process by which a drug moves from its site of administration to the systemic circulatory system
171
In terms of ADME, define metabolism
Any chemical alteration of a drug by the living system to enhance water solubility and hence excretion
172
In terms of ADME, define distribution
The reversible transfer of a drug to and from the systemic system
173
In terms of ADME, define excretion
The irreversible transfer of a drug from the systemic circulation
174
Define bioavailability
Refers to the fraction of the drug that is available in the bloody supply after administration
175
How can poor solubility be fixed?
By creating a salt as if the compound is ionisable, a salt may be more soluble
176
What are the factors affecting drug absorption?
- Acid stability
- Permeability
- Solubility
- Lipophilicity
- Metabolism
177
Define active transport
Movement against a concentration gradient by a transporter and requires ATP
178
Describe drug interactions with blood proteins
- Drugs can bind to macromolecules in the blood, known as plasma protein binding (PPB) or serum protein binding
- Compounds with high PPB are retained in the plasma and cannot distribute into the tissues
- Only unbound compound is available for distribution into tissues
179
Define drug-drug interactions
Effects which arise when multiple drugs are given to a patient
180
What are the two categories of metabolism and what do they mean?
Catabolism - breaks down into organic matter
Anabolism - uses energy to build up or construct components of cells such as proteins or nucleic acids
181
Define endogenous
Anything grown or created within us
182
Define drug metabolism
Any chemical alteration of a drug by the living system
183
What are the two phases of metabolism?
Phase I - oxidative transformations
Phase II - conjugation
184
Define CYP inhibition
Where a drug binds to a particular CYP and inhibits it, thereby preventing it from metabolising other substrates
185
Define CYP induction
Where a drug leads to the expression of greater levels of a particular CYP
186
Define prodrug
An inactive compound converted to an active compound in the body
187
Define tubular reabsorption
The removal of water and solutes from the filtrate, the water and solutes return to the blood via the peritubular capillaries
188
Define tubular secretion
Transport of excess solutes and wastes from the peritubular fluid into the tubular fluid
189
What are the three possible dosage forms with examples?
Liquid - solutions, syrups
Semisolid - creams, ointments, gels
Solid - tablet, capsules
190
