Block 2 - Enzyme Catalysis Flashcards Preview

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Flashcards in Block 2 - Enzyme Catalysis Deck (16):
1

What are most enzymes made out of?

Protein

2

How do enzymes help a reaction? Which 2 aspects do they NOT affect?

They increase rate of reaction.
Do not affect ΔG or Keq

3

How do pH and temperature affect enzymes? What are standard conditions for enzymes in the body?

Each enzyme has an optimum pH and temperature at which they work.
Standard conditions in the body are pH = 7 and temp 37 C. (Exceptions pH = 2 pepsin in stomach and pH = 9 alkaline phosphatase)

4

What are 6 types of enzyme classifications?

Oxidoreducatases
Transferases
Hydrolases
Lyases
Isomerases
Ligases

5

Describe the effects of oxidoreductases

Act as electron donators or acceptors
1 --> 1
No break/elongation of a molecule

6

Describe the effects of transferases

Catalyze the transfer a C-, N-, or P

7

Describe the effects of hydrolases

Catalyze cleavage of bonds by adding water
Substrate breaks into two parts

8

Describe the effects of lyases

Cleavage of C-C, C-S, or C-N bonds
Substrate breaks into two parts

9

Describe the effects of isomerases

Catalyze the reorganization of a molecule (isomer)
1-->1

10

Describe the effects of ligases

Form bonds between C and O,S, or N coupled with hydrolysis of high energy phosphatases

11

What is the active site of an enzyme?

A specific region on the enzyme where the reaction occurs. Substrate and potential required elements bind (high specificity)

12

What are prosthetic groups? Which are most common?

Stabilize the enzyme, most often by metal ions

13

Do cofactors bind to the substrate, the enzyme, or both? What is their role?

They can bind to either. They contribution is required for the reaction to occur.

14

How do coenymes help with enzyme reactions?

They act as shuttles, transfering a group from one reaction to another

15

What are isoenzymes? What makes them different?

Enzymes that catalyze the same reaction but vary kinetically, subtrate affinity, or in which tissue they work. They have the same Keq.

16

What is catalyze by strain?

An enzyme causes a substrate to bind in such a way that the bond becomes unstable and is more easily broken.