Introduction to enzymes

Question 1

List the biological functions of enzymes

Answer 1

Metabolic pathways
Signal transduction and cell regulation
Digestion
Movement
Energy production
Drug metabolism

Question 2

Can enzymes be targeted by drugs?

Answer 2

yes, for example, angiotensin-converting enzyme and hypertension

Question 3

What enzyme is a diagnostic marker of myocardial infarction?

Answer 3

Creatine phosphokinase

Question 4

What are the three main principles of enzymes?

Answer 4

They are catalysts,
They cannot alter the equilibrium of a reaction
They accelerate chemical reactions

Question 5

What is Vmax?

Answer 5

Mximum velocity of catalysis when substrate is in excess

Question 6

What is Km?

Answer 6

A measure of the enzyme-substrate complex. Higher values mean lower substrate-enzyme affinity

Question 7

[S] > Km ->

Answer 7

v=Vmax

Question 8

[S] =Km

Answer 8

v=Vmax/2

Question 9

[S]

Answer 9

v = Vmax x [S]/Km

Question 10

What are coenzymes

Answer 10

Helper molecules that p;ay an essential role in enzyme-catalyzed reactions

Question 11

What are the two subtypes of coenzymes?

Answer 11

Co-substrate and prosthetic groups

Question 12

What are the two ways enzymes are inhibited?

Answer 12

Irreversible and reversible inhibitions

Question 13

What are the two types of reversible enzyme inhibitors?

Answer 13

Competitive and noncompetitive

Question 14

How does competitive inhibition work

Answer 14

Enzyme can bind to substrate or competitive inhibitor but not both at the same time

Question 15

What distingushes noncompetitive inhibition?

Answer 15

Enzyme or enzyme substrate complex can bind to oncompetitive inhibitor

Question 16

What is the difinition of enzyme activity?

Answer 16

It is determined by amount of substrate converted per unit time at 25 degrees C, optimal pH, and substrate saturation