Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FA - Pharmacology > Pharm - Pharmacokinetics/-dynamics (Enzyme kinetics, Pharmacokinetics, & Dosage calculations) > Flashcards

Pharm - Pharmacokinetics/-dynamics (Enzyme kinetics, Pharmacokinetics, & Dosage calculations) Flashcards

Pg. 238-239 in First Aid 2014 Sections include: -Enzyme kinetics -Pharmacokinetics vs. pharmacodynamics -Pharmacokinetics -Dosage calculations

1
Q

What are the axes of the Michaelis-Menten kinetics graph?

A

x-axis: [S] = concentration of substrate, y-axis: Velocity (V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Draw the Michaelis-Menten kinetics graph, graph a reaction, including and labeling the following: (1) Km (2) Vmax (3) 1/2 Vmax (4) Saturation.

A

See p. 238 in First Aid 2014 for graph at top

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does Km relate to affinity of enzyme for its substrate?

A

Km is inversely related to the affinity of the enzyme for its susbstrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does Vmax relate to enzyme concentration?

A

Vmax is directly proportional to the enzyme concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of curve do most enzymatic reactions exhibit? What does this mean?

A

Most enzymatic reactions follow a hyperbolic curve (follow Michaelis-Menten kinetics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes an enzymatic reaction to exhibit a sigmoid curve? Give an example of such a reaction.

A

Enzymatic reactions that exhibit a sigmoid curve usually indicate cooperative kinetics (i.e.., hemoglobin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the axes of the Lineweaver-Burk plot?

A

x-axis: 1/[S], y-axis: 1/V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Draw the Lineweaver-Burk plot, graph a reaction, including and labeling the following: (1) 1/-Km (2) 1/V max (3) slope = Km/Vmax.

A

See p. 238 in First Aid 2014 for middle graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the slope of the Lineweaver-Burk plot?

A

slope = Km/Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to Vmax as the y-intercept of the Lineweaver-Burk plot is increased?

A

increase y-intercept, decrease Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

On the Lineweaver-Burk plot, what does it mean to move the x-intercept to the right (in terms of numerical value)? What effect does this have on Km and affinity?

A

The further to the right the x-intercept (i.e., closer to zero), the greater the Km and the lower the affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Graph the following lines on the Lineweaker-Burk plot: (1) Competitive inhibitor (2) Noncompetitive inhibitor (3) Uninhibited.

A

See p. 238 in First Aid 2014 for bottom graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do competitive versus noncompetitive inhibitors interact with their own kind?

A

Competitive inhibitors cross each other competitively, whereas noncompetitive inhibitors do not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Does each of the following resemble substrate: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Yes (2) Yes (2) No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is each of the following overcome by increasing [S]: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Yes (2) No (3) No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Does each of the following bind the active site: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Yes (2) Yes (3) No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What effect does each of the following have on Vmax: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Unchanged (2) Decrease (3) Decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What effect does each of the following have on Km: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Increase (2) Unchanged (3) Unchanged

19
Q

What effect does each of the following have on potency/efficacy: (1) Competitive inhibitors, reversible (2) Competitive inhibitors, irreversible (3) Noncompetitive inhibitors?

A

(1) Decrease potency (2) Decrease efficacy (3) Decrease efficacy

20
Q

In general, what does pharmacokinetics study? Give 4 specific examples.

A

The effects of the body on the drug; (1) Absorption (2) Distribution (3) Metabolism (4) Excretion; Think: “ ADME”

21
Q

In general, what does pharmacodynamics study? Give 4 specific examples of concepts.

A

The effects of the drug on the body; Includes concepts of (1) receptor binding (2) drug efficacy (3) drug potency (4) toxicity.

22
Q

Define Bioavailability. What is its abbreviation?

A

Bioavailability (F): Fraction of administered drug that reaches systemic circulation unchanged

23
Q

What is the bioavailability of an IV dose?

A

For an IV dose, F = 100%

24
Q

What is the bioavailability of an oral dose, and why?

A

Orally: F typically < 100% due to incomplete absorption and first-pass metabolism

25
Q

Define Volume of distribution (Vd)

A

Theoretical volume occupied by the total absorbed drug amount at the plasma concentration.

26
Q

What alters the apparent Vd of plasma protein-bound drugs?

A

Apparent Vd of plasma-protein bound drugs can be altered by liver and kidney disease (decreased protein binding, increased Vd)

27
Q

What is a minor but important consideration in calculating volume of distribution?

A

Drugs may distribute in more than one compartment

28
Q

What is the equation for Vd?

A

Vd = amount of drug in the body / plasma drug concentration

29
Q

Into what compartment do drugs with a low Vd distribute? What characterizes such drugs?

A

Blood (4-8 L); Large/charged molecules, Plasma protein bound

30
Q

Into what compartment do drugs with a medium Vd distribute? What characterizes such drugs?

A

ECF; Small hydrophilic molecules

31
Q

Into what compartment do drugs with a high Vd distribute? What characterizes such drugs?

A

All tissues including fat; Small lipophilic molecules, especially if bound to tissue protein

32
Q

What defines half-life (t 1/2)?

A

The time required to change the amount of drug in the body by 1/2 during elimination (or constant infusion)

33
Q

Of what type of elimination is half-life a property?

A

Property of first-order elimination

34
Q

What is the equation for half-life?

A

t 1/2 = (0.693 x Vd) / CL

35
Q

At the following half-lives, what percentage of drug remains: (1) 1 (2) 2 (3) 3 (4) 4?

A

(1) 50% (2) 25% (3) 12.5% (4) 6.25%

36
Q

Define Clearance (CL).

A

The volume of plasma cleared of drug per unit time

37
Q

What are 3 factors/conditions that may impair clearance.

A

Clearance may be impaired with defects in cardiac, hepatic, or renal function.

38
Q

What is the equation for Clearance (CL)?

A

CL = rate of elimination of drug / plasma drug concentration = Vd x Ke (elimination constant)

39
Q

What is the equation for the loading dose?

A

Loading dose = (Cp x Vd) / F; Cp = target plasma concentration at steady state,

40
Q

What is the equation for the maintenance dose?

A

Maintenance dose = (Cp x CL x tao) / F; Cp = target plasma concentration at steady state, tao = dosage interval (time between doses), if not administered continuously

41
Q

What happens to maintenance versus loading doses in renal or liver disease?

A

In renal or liver disease, maintenance dose decreases and loading dose is usually unchanged

42
Q

On what factor does time to steady state depend? Of what 2 factors is it independent?

A

Time to steady state depends primarily on t 1/2 and is independent of dose and dosing frequency

43
Q

In Michaelis-Menten kinetics, what is Km?

A

Km is [S] at 1/2 V max

FA - Pharmacology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions