Enzymes

Question 1

What do enzymes do?

Answer 1

Speed up metabolic reactions by lowering energy barriers

Question 2

Catalyst

Answer 2

Chemical agent that speeds up reaction without being consumed by the reaction

Question 3

Activation Barrier

Answer 3

Every chemical reaction between molecules involves both bond breaking and forming

Question 4

Activation Energy (EA)

Answer 4

-Is initial amount of energy needed to start chemical reaction
-is often supplied in form of heat from surroundings in a system

Question 5

How enzymes lower the activation energy barrier

Answer 5

by catalyzing reactions

Question 6

Substrate

Answer 6

reactant enzyme acts on

Question 7

Active site

Answer 7

Region on enzyme where substrate binds

Question 8

Induced fit of a substrate

Answer 8

Brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction

Question 9

Active site can lower an Activation energy barrier by

Answer 9

-orienting substrates correctly
- straining substrate bonds
- providing a favourable microenvironment
- covalently bonding to the substrate

Question 10

Cofactors

Answer 10

Non protein enzyme helpers.

Question 11

Conenzymes

Answer 11

Organic cofactors

Question 12

Competitive inhibitors

Answer 12

Bind to active site of an enzyme, competing with the substrate

Question 13

Non competitive inhibitors

Answer 13

Bind to another part of an enzyme changing the function

Question 14

Allosteric Regulation

Answer 14

When proteins function at one site is affected by binding of a regulatory molecule at another site

Question 15

Cooperativity

Answer 15

Form of allosteric regulation that can amplify enzyme activity

Question 16

in feedback inhibition

Answer 16

The end product of a metabolic pathway shuts down the pathway