Enzymes

Question 1

Exergonic Reactions

Answer 1

Energy RELEASED
∆G = (-)

Question 2

Endergonic Reactions

Answer 2

Energy REQUIRED
∆G = (+)

Question 3

Oxidoreductase

Answer 3

Redox reactions that involve the transfer of e-

Question 4

transferases

Answer 4

move functional group from one molecule to another

Question 5

hydrolases

Answer 5

Catalyze cleavage with the addition of H2O

Question 6

Lyases

Answer 6

catalyze cleavage without the addition of H2O and without the transfer of e-
the reverse reaction (synthesis) is often more important biologically

Question 7

isomerase

Answer 7

catalyze the interconversion of isomers, including both constitutional isomers and stereoisomers

Question 8

ligases

Answer 8

join two large biomolecules, often of the same type

Question 9

kinases

Answer 9

ADD a phosphate group
type of transferase

Question 10

Phosphatase

Answer 10

REMOVES a phosphate group
type of transferase

Question 11

Phosphorylase

Answer 11

introduces a phosphate group into an organic molecule, notable glucose

Question 12

Michaelis-Menten Equation

Km =
V0 =

Answer 12

Km =( K(-1) + K(2) )/ K(1)

the [S] at which an enzyme runs at half its Vmax

V0 = Vmax ([S]/([S]+Km))

Question 13

Cofactors

Answer 13

metal cation that is required by some enzymes

Question 14

coenzyme

Answer 14

organic moelcule that is required by some enzymes

Question 15

Feedback Inhibition

Answer 15

An enzyme is inhibited by high levels of a product from later in the same pathway

Question 16

Reversible inhibition

Answer 16

the ability to replace the inhibitor with a compound of greater affinity or to remove it using mild labrotory treatement

Question 17

Competitive inhibition

Answer 17

when the inhibitor is similar to the substrate and binds at the active site, blocking the substrate from binding
can be overcome by adding more substrate

Question 18

Uncompetitve inhibition

Answer 18

when the inhibitor binds only with the enzyme substrate complex
Vmax and Km both decrease

Question 19

Noncompetitive inhibition

Answer 19

When the inhibitor binds with equal affinity to the enzyme and the enzyme-substrate complex
Vmax decreases, Km is unchanged

Question 20

Mixed Inhibition

Answer 20

when the inhibitor binds with unequal affinity to the enzyme and the enzyme complex
Vmax decreases, Km increases or decreases depending on if the inhibitor has high affinity for the enzyme or enzyme-substrate complex