Chapter 6/8

Question 1

Oxidoreductases

Answer 1

Transfer of electrons

Question 2

Transferases

Answer 2

Transfers functional groups between molecules

Question 3

Hydrolases

Answer 3

Cleaves a molecule by addition of water

Question 4

Lyases

Answer 4

Adds or removes atoms of functional groups to form a double bond

Question 5

Isomerases

Answer 5

Moves functional groups within a molecule

Question 6

Ligases

Answer 6

Joins 2 molecules through ATP hydrolysis

Question 7

Apoenzyme

Answer 7

An enzyme without a cofactor

Question 8

Holoenzyme

Answer 8

A catalytically active enzyme

Question 9

Cofactors

Answer 9

Small molecules required by many enzymes for catalytic activity

Question 10

Coenzyme

Answer 10

Type of Cofactor: small organic molecules, derived from vitamins

Question 11

Metals

Answer 11

Type of Cofactor

Question 12

Prosthetic groups

Answer 12

Tightly bound coenzyme

Question 13

Cosubstrates

Answer 13

Loosely bound coenzymes, bind to the enzyme and are released from it

Question 14

Chymotrypsin Mechanism step 1

Answer 14

Substrate binds

Question 15

Chymotrypsin Mechanism step 2

Answer 15

Oxygen of side chain of serine makes nucleophilic attack on carbonyl carbon of target peptide bond

Question 16

Chymotrypsin Mechanism step 3

Answer 16

Tetrahedral intermediate collapses to generate acyl enzyme

Question 17

Chymotrypsin Mechanism step 4

Answer 17

Release of amine component (Proton from positive charged His residue goes to amino group of substrate; Also first stage of hydrolytic rxn: Acylation of enzyme)

Question 18

Chymotrypsin Mechanism step 5

Answer 18

Water molecule takes place of amine component that was just released

Question 19

Chymotrypsin Mechanism step 6

Answer 19

OH- ion attacks carbonyl carbon atom of acyl group forming tetrahedral intermediate

Question 20

Chymotrypsin Mechanism step 7

Answer 20

tetrahedral intermediate collapses forming COOH product

Question 21

Chymotrypsin Mechanism step 8

Answer 21

COOH component released