Pharm p. 242-244

Question 1

What variable represents Michaelis-Menten constant?

Answer 1

Km

Question 2

enzymatic reactions that exhibit a sigmoid curve usually —– kinetics.

Answer 2

indicate cooperative

Question 3

Km is —- related to the affinity of the enzyme for its substrate.

Answer 3

inversely

Question 4

Most enzymatic reactions follow hyperbolic

curves like:

Answer 4

Michaelis-Menten kinetics

Question 5

Vmax is directly proportional to the enzyme —-.

.

Answer 5

concentration

Question 6

Formula for Km? Km =

Answer 6

Km = [S] at 1/2 Vmax

Question 7

According to Michaelis-Menten kinetics, Vmax is the point at which the enzymes are —-.

Answer 7

saturated

Question 8

In Lineweaver-Burk plot, the higher the y-intercept, the —  Vmax.

Answer 8

lower

Question 9

In Lineweaver-Burk plot, on the x-axis, the closer to zero, the —- the Km and the —- the affinity.

Answer 9

greater

lower

Question 10

How can one distinguish btw reversible and non-reversible inhibitors on the Lineweaver-Burk plot?

Answer 10

Reversible competitive inhibitors cross each
other competitively, whereas noncompetitive
inhibitors do not.

Question 11

Do irreversible Competitive inhibitors bind to the active site?

Answer 11

Yes, only Non-comp. don’t.

Question 12

T or F? Irreversible Competitive inhibitors incr Vmax.

Answer 12

F. decr

Question 13

T or F? reversible Competitive inhibitors dcr Km.

Answer 13

F. incr

Question 14

T or F? Irreversible Competitive inhibitors incr efficacy.

Answer 14

F. decr

Question 15

T or F? reversible Competitive inhibitors decr efficacy.

Answer 15

F. Unchanged

Question 16

Which kind of inhibitors can be overcome by incr [S]?

Answer 16

reversible Competitive inhibitors

Question 17

Formula for Vd?

Answer 17

Vd = (amount of drug in the body) /

(plasma drug concentration)

Question 18

Liver and kidney disease decr protein binding to drugs causing — Vd.

Answer 18

incr

Question 19

Drugs that are large/charged molecules and plasma protein bound have a —- Vd.

Answer 19

Low

Question 20

Drugs that are small lipophilic molecules and bound

to tissue protein are found in which tissues?

Answer 20

All tissues, specially fat tissue

Question 21

Formula for Cl?

Answer 21

CL= (rate of elimination of drug) /

(plasma drug concentration)

Question 22

Formula for Cl in terms of Vd?

Answer 22

Cl = Vd × Ke (elimination constant)

Question 23

If a drug is mostly found in the blood, what is its Vd?

Answer 23

low

Question 24

Time to steady state depends primarily on — and is independent of —- —-.

Answer 24

t1/2

dose and dosing frequency

Question 25

Loading dose =

Answer 25

Loading dose = (Cp × Vd) / F

Question 26

A drug infused at a constant rate takes --- half-lives | to reach steady state.

Answer 26

4–5

Question 27

Maintenance dose =

Answer 27

MD = (Cp × CL × τ) / F

Question 28

t1/2 =

Answer 28

t1/2 = (0.693 × Vd) / CL

Question 29

It takes --- half-lives to reach 90% of the steady-state level.

Answer 29

3.3

Question 30

In renal or liver disease, maintenance dose ---  and | loading dose is usually -----.

Answer 30

decr | unchanged

Question 31

If a drug is mostly found in the ECF, what are the properties of the drug?

Answer 31

Made out of small hydrophilic molecules

Question 32

after 4 half-lives, what % of the drug is remaining in body?

Answer 32

6.25%

Question 33

A constant amount of drug eliminated per unit time is called?

Answer 33

Zero-order elimination

Question 34

To treat overdose of a weak acidic drug one must administer what kind of drug?

Answer 34

basic drug

Question 35

To treat overdose amphetamines, give which drug?

Answer 35

ammonium chloride

Question 36

Examples of 3 drugs with Zero-order elimination at | high or toxic concentrations?

Answer 36

Phenytoin, Ethanol, and Aspirin "PEA"

Question 37

A constant fraction of drug eliminated per unit time is called?

Answer 37

First-order elimination

Question 38

Another name for Zero-order elimination?

Answer 38

Capacity-limited elimination.

Question 39

Give 4 examples of acidic drug OD that Bicarbonate can treat?

Answer 39

phenobarbital methotrexate aspirin TCAs

Question 40

Another name for First-order elimination?

Answer 40

Flow-dependent elimination

Question 41

In Phase II of metabolism, what is Conjugation referred to? "GAS"

Answer 41

Glucuronidation, Acetylation, Sulfation

Question 42

Which of the met. phases yields metabolites that are renally excreted? and why?

Answer 42

Phase II | Because the metabolites are very polar and inactive