Enzymes

Question 1

Describe an enzyme and the two types

Answer 1

Protein that facilitates a chemical reaction/acts as a catalyst

1. Simple: protein only
2. Conjugated: protein part (the apoenzyme) + non-protein part (coenzyme/cofactor)

Question 2

Describe a coenzyme

Answer 2

A compound derived from vitamins that assists an enzyme

E.g. NAD+

Question 3

Cofactor

Answer 3

Metal ion that assists an enzyme

Question 4

Apoenzyme

Answer 4

Protein only part of an enzyme

Question 5

When is an enzyme-substrate complex formed?

Answer 5

When a substrate binds to the enzyme-active site

allows the substrate to undergo its chemical reaction faster

Question 6

What are the two mechanisms (models) of enzyme action?

Answer 6

1. Lock and key model - active site is fixed and the substrate must fit precisely into it
2. Induced fit model - shape of active site changes to accommodate substrate

Question 7

Name 4 factors affecting enzyme activity….

Answer 7

1. Temperature - enzymes have an optimum temperature to function
2. pH - change in pH can result in denaturation of loss of function
3. Substrate concentration - activity increases until saturation point
4. Enzyme concentration - reaction rates increases with increase in enzyme concentration

Question 8

Name the 3 types of enzyme inhibition

Answer 8

1. reversible competitive
2. reversible non-competitve
3. irreversible

Question 9

What’s a substrate?

Answer 9

The reactant upon which an enzyme acts

Question 10

What’s the active site?

Answer 10

Where a substrate binds on an enzyme

Question 11

What’s a zymogen?

Answer 11

An enzyme in an inactive form