Chapter 8 - Microbial Metabolism

Question 1

holoenzyme

Answer 1

contains protein and nonprotein molecules

Question 2

apoenzyme

Answer 2

protein portion

Question 3

simple enzyme

Answer 3

consist of protein alone

Question 4

cofactors

Answer 4

nonprotein portion; typically metal ions (ex: iron)

Question 5

coenzymes

Answer 5

organic molecules (ex: vitamins)

Question 6

oxidoreductases

Answer 6

transfer electrons from one substrate to another (Class I enzyme)

Question 7

dehydrogenases

Answer 7

transfer H+ from one to another (Class I enzyme)

Question 8

transferases

Answer 8

transfer functional groups (Class II enzyme)

Question 9

hydrolases

Answer 9

cleave bonds on molecules with the addition of water (Class III enzyme)

Question 10

lysases

Answer 10

add or remove groups from double-bonded substrates (Class IV enzyme)

Question 11

isomerases

Answer 11

change a substrate into its isomeric form (Class V enzyme)

Question 12

ligases

Answer 12

formation of bonds with the input of ATP and removal of water (Class VI enzyme)

Question 13

constitutive enzymes

Answer 13

always present, always produced in equal amounts or at equal rates, regardless of the amount of substrate

Question 14

regulated enzymes

Answer 14

not constantly present; production is turned on (induced) or turned off (repressed) in response to changes in the substrate concentration

Question 15

labile

Answer 15

chemically unstable enzymes

Question 16

oxidation

Answer 16

a substance loses electrons, or is oxidized (the amount of positive charge increases)

Question 17

reduction

Answer 17

a substance gains electrons , or is reduced (the amount of positive charge is reduced)