PHM 819 Module 2: Transport, Absorption,
and Distribution Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
Absorption - CORRECT ANSWER How the drug enters the body through various
physiological barriers
Distribution - CORRECT ANSWER Where a chemical ends up after absorption; it
must be distributed at a sufficient concentration of target site to work effectively
Metabolism - CORRECT ANSWER How the body chemical modifies a drug; may
inactive the drug or even increase activity of the drug
Excretion - CORRECT ANSWER How the body removes the drug (mainly through
kidney, liver, and feces)
What is maximum concentration (Cmax) in terms of pharmacokinetics? Why is this
important for a drug? - CORRECT ANSWER It is the maximum concentration a drug
reaches in the body; this is important to help predict the therapeutic benefits/toxicity of a drug
What is the half life of a drug? - CORRECT ANSWER The time it takes for a drug to
drop to 1/2 its Cmax
What is Tmax? - CORRECT ANSWER The amount of time it takes a drug to reach
Cmax
Area under the curve (AUC) - CORRECT ANSWER The total area under the curve of
a drug concentration over time, of which measures the total exposure to a drug
What are transporters? Why is it important to identify these in pharmacology? - CORRECT
ANSWER Proteins that assist movement of small, soluble molecules across the lipid
bilayer through facilitated or active diffusion.
, Identification of which transporters interact with a drug can help to improve drug
bioavailablity, efficacy, limit toxicity, and prevent drug-drug interactions (drugs may compete
for same binding site).
What is filtration? What are factors that affect filtration? - CORRECT
ANSWER Filtration is movement of a molecule down its osmotic gradient; no energy
input needed.
Factors: molecule size, pore size, ratio of cell surface area to pore size, blood flow
What is passive (simple) diffusion? What factors drive it? What type of solutes (in terms of
solubility and size) may use passive diffusion? - CORRECT ANSWER Passive
diffusion is the spontaneous (no energy required) movement of molecules across the lipid
membrane from a higher to lower concentration. Equilibrium is reached (rate of diffusion
same on either side) once there is an equal number of molecules on each side.
Factors: blood flow, concentration gradient, transport surface area, ionization state,
lipophilicity
Small, partially water-soluble molecules
How does blood flow help drive simple diffusion? - CORRECT ANSWER Blood flow
keeps a concentration gradient between the blood and adjacent tissues, since the movement of
blood keeps drug concentration lower in the blood * (see book for clarification)
How does lipophilicity help drive simple diffusion? - CORRECT
ANSWER Substances with a higher permeability in lipids can more easily cross the
bilayer lipid membrane. This is because the core if formed of hydrophobic fatty acid tails
What is a permeability coefficient? What are examples of biologically important molecules
with higher and lower values? - CORRECT ANSWER Permeability coefficient is a
measure in cm/s of how fast a substance can cross the lipid bilayer using passive diffusion
and Distribution Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
Absorption - CORRECT ANSWER How the drug enters the body through various
physiological barriers
Distribution - CORRECT ANSWER Where a chemical ends up after absorption; it
must be distributed at a sufficient concentration of target site to work effectively
Metabolism - CORRECT ANSWER How the body chemical modifies a drug; may
inactive the drug or even increase activity of the drug
Excretion - CORRECT ANSWER How the body removes the drug (mainly through
kidney, liver, and feces)
What is maximum concentration (Cmax) in terms of pharmacokinetics? Why is this
important for a drug? - CORRECT ANSWER It is the maximum concentration a drug
reaches in the body; this is important to help predict the therapeutic benefits/toxicity of a drug
What is the half life of a drug? - CORRECT ANSWER The time it takes for a drug to
drop to 1/2 its Cmax
What is Tmax? - CORRECT ANSWER The amount of time it takes a drug to reach
Cmax
Area under the curve (AUC) - CORRECT ANSWER The total area under the curve of
a drug concentration over time, of which measures the total exposure to a drug
What are transporters? Why is it important to identify these in pharmacology? - CORRECT
ANSWER Proteins that assist movement of small, soluble molecules across the lipid
bilayer through facilitated or active diffusion.
, Identification of which transporters interact with a drug can help to improve drug
bioavailablity, efficacy, limit toxicity, and prevent drug-drug interactions (drugs may compete
for same binding site).
What is filtration? What are factors that affect filtration? - CORRECT
ANSWER Filtration is movement of a molecule down its osmotic gradient; no energy
input needed.
Factors: molecule size, pore size, ratio of cell surface area to pore size, blood flow
What is passive (simple) diffusion? What factors drive it? What type of solutes (in terms of
solubility and size) may use passive diffusion? - CORRECT ANSWER Passive
diffusion is the spontaneous (no energy required) movement of molecules across the lipid
membrane from a higher to lower concentration. Equilibrium is reached (rate of diffusion
same on either side) once there is an equal number of molecules on each side.
Factors: blood flow, concentration gradient, transport surface area, ionization state,
lipophilicity
Small, partially water-soluble molecules
How does blood flow help drive simple diffusion? - CORRECT ANSWER Blood flow
keeps a concentration gradient between the blood and adjacent tissues, since the movement of
blood keeps drug concentration lower in the blood * (see book for clarification)
How does lipophilicity help drive simple diffusion? - CORRECT
ANSWER Substances with a higher permeability in lipids can more easily cross the
bilayer lipid membrane. This is because the core if formed of hydrophobic fatty acid tails
What is a permeability coefficient? What are examples of biologically important molecules
with higher and lower values? - CORRECT ANSWER Permeability coefficient is a
measure in cm/s of how fast a substance can cross the lipid bilayer using passive diffusion
