Enzymes

Question 1

Ligases

Answer 1

responsible for joining two large biomolecules

Question 2

Isomerases

Answer 2

catalyze the interconversion of isomers, including both constitutional and stereoisomers

Question 3

Lyases

Answer 3

catalyze cleavage without the addition of water and without the transfer of electrons
Reverse is also catalyzed by lyases but are often called synthases (because they are synthesizing)

Question 4

Hydrolases

Answer 4

catalyze cleavage with the addition of water

Question 5

Oxidoreductases

Answer 5

catalyze oxidation-reduction reactions that involve the transfer of electrons

Question 6

transferases

Answer 6

move a functional group from one molecule to another molecule

Question 7

Enzyme Function

Answer 7

lower the activation energy but do not alter the free energy (delta G) or the enthalpy (delta H) change of the reaction, nor the final equilibrium position

only change the rate (kinetics)

Question 8

Saturation Kinetics

Answer 8

as substrate concentration increases the reaction rate also increases until a maximum value is reached

v= Vmax [S] / Km + [S]
at one half of Vmax, [S] = Km

Question 9

Curve of Cooperative Enzymes

Answer 9

Sigmoidal

Question 10

Competitive Enzymes

Answer 10

Bind to Active Site
Increase Km
No impact on Vmax

Question 11

Noncompetitive Enzymes

Answer 11

Bind to Allosteric Site
No change in Km
Decrease Vmax

Question 12

Mixed Inhibition Enzymes

Answer 12

Bind to Allosteric Site
Increases OR Decreases Km (depending on affinity)
Decreases Vmax

Question 13

Uncompetitive Enzymes

Answer 13

Bind to Allosteric Site
Decrease Km
Decrease Vmax

Question 14

Cofactors

Answer 14

inorganic molecules or metal ions, minerals

Question 15

Coenzymes

Answer 15

organic molecules, vitamins (or vitamin derivatives)

Question 16

Michaelis-Menten Equation

Answer 16

V= Vmax [S] / Km + [S]

Question 17

Km= [S], when?

Answer 17

the reaction rate is half of Vmax

Question 18

Km represents

Answer 18

the concentration of substrate when half of the enzymes active sites are full

Question 19

Km trends

Answer 19

high Km means lower affinity

lower Km means hight affinity

Question 20

Lineweaver-Burk Plots:
y-axis
x-axis

Answer 20

y-axis 1/Vmax

x-axis -1/Km

Question 21

Factors that Affect Enzyme Function

Answer 21

Temperature
pH
Salinity

Question 22

Allosteric Enzymes

Answer 22

have multiple binding sites and one active site, and at least one other site that can regulate the availability of the the active site called an allosteric site

Question 23

Zymogens

Answer 23

they are preenzymes that are not yet activated until the regulatory domain is removed or altered to expose the active site