BIOM 3090 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Question:
1. Explain the NAPRA drug schedule.
Answer:
NAPRA I: prescription needed to obtain drug from pharmacist. Includes
prescription drugs (Pr), narcotics (N), controlled substances (C1, C2, C3), and
targeted substances (TS).
NAPRA II: prescription not required but must be dispensed by a pharmacist
(behind the counter)
NAPRA III: can be obtained from a pharmacy without the need of pharmacist
Unscheduled: can be obtained at retail stores and pharmacies
Question:
2. Differentiate between pharmacodynamics and
pharmacokinetics.
Answer:
Pharmacodynamics = actions of drugs on the body
Pharmacokinetics = actions of body on the drug
Question:
3. What are the 2 qualities of useful drugs?
Answer:
1. Must have properties enabling transport from the site of administration to the
target site (biophase).
2. Should be inactivated and excreted from the body at a reasonable rate to avoid
duration of action concerns.
Question:
4. Describe the primary, secondary, tertiary, and quaternary
structure of proteins.
Answer:
Primary = sequence of AAs
Secondary = formed when AAs interact with nearby AAs on the same protein
(mainly hydrogen bonds)
Tertiary = formed when AAs interact with more distant AAs on the same protein
(hydrogen, ionic, and disulfide/covalent bonds)
Quaternary = formed when multiple polypeptides interact
,Question:
5. What 3 factors affect the selectivity of a drug for its
receptor?
Answer:
1. Size = minimum size needed to impart specificity of action and allow binding to
select receptors (~ 100MW), maximum size limit allowing reasonable movement
through the body to sites of action (~1000MW)
2. Charge = drugs and receptors interact by means of chemical forces or bonds
(Van der Waals, hydrophobic, electrostatic, and covalent). Drugs that bind to
receptors through multiple weak bonds are typically more selective (require a
more precise fit). The total sum of intermolecular forces dictates the affinity of the
drug for its receptor.
3. Shape and atomic composition = dictates the ability of the drug to bind to its
receptor via a lock and key mechanism. Stereochemistry of enantiomeric
compounds also influences drug-receptor fit (the R- or S- version of the drug
may be more potent due to better fit with the receptor)
Question:
6. What are suicide substrates?
Answer:
Drugs that bind to their receptor via covalent bonds which are usually irreversible.
Cells must synthesize new receptors to replace those bound to the suicide
substrate.
Question:
7. What 2 factors influencing the selectivity of drug action?
Answer:
1. Cell-type specificity of receptor subtypes: the fewer cell types a specific
receptor can be present on (restricted cell type distribution) the more selective
the drug action
2. Cell-type specificity of receptor-effector coupling mechanisms: the more the
effects of signalling through the same receptor type on different cell types differs,
the more selective the drug action.
Question:
8. Provide an example of a ion channel activated by
intracellular molecules
Answer:
Sulfonylurea receptor (SUR1) --> regulates the ATP-dependent K+ channel in
pancreatic β cells (G6P in cytoplasm stimulates cascade for insulin release).
, Question:
9. Describe the typical activation of a G-protein coupled
receptor.
Answer:
1. Agonist binds to the transmembrane receptor and activates G-protein (GDP
bound to the heterotrimeric G-protein is exchanged for GTP).
2. α-GTP subunit of the protein diffuses and binds to and activates the effector.
3. Effector activation is terminated when the agonist unbinds from the
transmembrane receptor; GTP is hydrolyzed to GDP and the heterotrimeric G
protein is reconstituted.
Question:
10. What are the 5 major G proteins? What are their actions?
Answer:
1. Gs: activates Ca++ channels and activates adenylyl cyclase.
2. Gi: activates K+ channels and inhibits adenylyl cyclase
3. Go: inhibits Ca++ channels.
4. Gq: activates phospholipase C.
5. G12/13: diverse ion transporter interactions
Question:
11. Receptor tyrosine kinases and tyrosine-kinase associated
receptors belong to the family of transmembrane
receptors with enzymatic cytosolic domains. Briefly
explain how they work.
Answer:
1. Receptor tyrosine kinase receptors
i) endogenous ligands such as insulin, PDGF, VEGF bind to receptors and induce
dimerization and effector activation
ii) SH2 domains commonly act as effectors and phosphorylate signalling
molecules such as Grb2
2. Tyrosine-kinase associated receptors
i) binding of γ-interferon, growth hormone, and prolactin induce dimerization
ii) dimerization allows an intracellular tyrosine kinase (ex: JAKs) to bind and
phosphorylate proteins (ex: STATs) which translocate to the nucleus and exert
genomic effects
CORRECT ANSWERS
Question:
1. Explain the NAPRA drug schedule.
Answer:
NAPRA I: prescription needed to obtain drug from pharmacist. Includes
prescription drugs (Pr), narcotics (N), controlled substances (C1, C2, C3), and
targeted substances (TS).
NAPRA II: prescription not required but must be dispensed by a pharmacist
(behind the counter)
NAPRA III: can be obtained from a pharmacy without the need of pharmacist
Unscheduled: can be obtained at retail stores and pharmacies
Question:
2. Differentiate between pharmacodynamics and
pharmacokinetics.
Answer:
Pharmacodynamics = actions of drugs on the body
Pharmacokinetics = actions of body on the drug
Question:
3. What are the 2 qualities of useful drugs?
Answer:
1. Must have properties enabling transport from the site of administration to the
target site (biophase).
2. Should be inactivated and excreted from the body at a reasonable rate to avoid
duration of action concerns.
Question:
4. Describe the primary, secondary, tertiary, and quaternary
structure of proteins.
Answer:
Primary = sequence of AAs
Secondary = formed when AAs interact with nearby AAs on the same protein
(mainly hydrogen bonds)
Tertiary = formed when AAs interact with more distant AAs on the same protein
(hydrogen, ionic, and disulfide/covalent bonds)
Quaternary = formed when multiple polypeptides interact
,Question:
5. What 3 factors affect the selectivity of a drug for its
receptor?
Answer:
1. Size = minimum size needed to impart specificity of action and allow binding to
select receptors (~ 100MW), maximum size limit allowing reasonable movement
through the body to sites of action (~1000MW)
2. Charge = drugs and receptors interact by means of chemical forces or bonds
(Van der Waals, hydrophobic, electrostatic, and covalent). Drugs that bind to
receptors through multiple weak bonds are typically more selective (require a
more precise fit). The total sum of intermolecular forces dictates the affinity of the
drug for its receptor.
3. Shape and atomic composition = dictates the ability of the drug to bind to its
receptor via a lock and key mechanism. Stereochemistry of enantiomeric
compounds also influences drug-receptor fit (the R- or S- version of the drug
may be more potent due to better fit with the receptor)
Question:
6. What are suicide substrates?
Answer:
Drugs that bind to their receptor via covalent bonds which are usually irreversible.
Cells must synthesize new receptors to replace those bound to the suicide
substrate.
Question:
7. What 2 factors influencing the selectivity of drug action?
Answer:
1. Cell-type specificity of receptor subtypes: the fewer cell types a specific
receptor can be present on (restricted cell type distribution) the more selective
the drug action
2. Cell-type specificity of receptor-effector coupling mechanisms: the more the
effects of signalling through the same receptor type on different cell types differs,
the more selective the drug action.
Question:
8. Provide an example of a ion channel activated by
intracellular molecules
Answer:
Sulfonylurea receptor (SUR1) --> regulates the ATP-dependent K+ channel in
pancreatic β cells (G6P in cytoplasm stimulates cascade for insulin release).
, Question:
9. Describe the typical activation of a G-protein coupled
receptor.
Answer:
1. Agonist binds to the transmembrane receptor and activates G-protein (GDP
bound to the heterotrimeric G-protein is exchanged for GTP).
2. α-GTP subunit of the protein diffuses and binds to and activates the effector.
3. Effector activation is terminated when the agonist unbinds from the
transmembrane receptor; GTP is hydrolyzed to GDP and the heterotrimeric G
protein is reconstituted.
Question:
10. What are the 5 major G proteins? What are their actions?
Answer:
1. Gs: activates Ca++ channels and activates adenylyl cyclase.
2. Gi: activates K+ channels and inhibits adenylyl cyclase
3. Go: inhibits Ca++ channels.
4. Gq: activates phospholipase C.
5. G12/13: diverse ion transporter interactions
Question:
11. Receptor tyrosine kinases and tyrosine-kinase associated
receptors belong to the family of transmembrane
receptors with enzymatic cytosolic domains. Briefly
explain how they work.
Answer:
1. Receptor tyrosine kinase receptors
i) endogenous ligands such as insulin, PDGF, VEGF bind to receptors and induce
dimerization and effector activation
ii) SH2 domains commonly act as effectors and phosphorylate signalling
molecules such as Grb2
2. Tyrosine-kinase associated receptors
i) binding of γ-interferon, growth hormone, and prolactin induce dimerization
ii) dimerization allows an intracellular tyrosine kinase (ex: JAKs) to bind and
phosphorylate proteins (ex: STATs) which translocate to the nucleus and exert
genomic effects
