#Question id: 635
#Section 2: General Biology
The enymatic rate constant (kcat/Km) of orotidine 5ʹ-phosphate decarboxylase is 6 x 107 M-1s-1 and the nonenzymatic rate constant (kn) is 3 x 10-16 s-1. What is the value of the enzymeʹs catalytic proficiency?
#Question id: 636
#Section 2: General Biology
DNA polymerase contains a lysine residue that is important for binding to DNA. Mutations were found that converted this lysine to either glutamate, glycine, valine, or arginine. Which mutations would be predicted to be the most and least harmful to the ability of the enzyme to bind DNA?
|
Most |
Least |
|
|
(A) |
Valine |
Aspartate |
|
(B) |
Glycine |
Arginine |
|
(C) |
Arginine |
Glycine |
|
(D) |
Glutamate |
Arginine |
#Question id: 638
#Section 2: General Biology
Match the following class of enzymes with them
|
Enzyme |
Class of enzyme |
|
A. Hexokinase |
1 |
|
B. Phosphoglucoisomerase |
2 |
|
C. Glyceraldehyde 3-phosphate dehydrogenase |
3 |
|
D. Phosphoglycerate mutase |
4 |
|
E. Enolase |
5 |
|
F. Aldolase |
#Question id: 639
#Section 2: General Biology
Match the coenzymes in column I enzymes to class of enzymes in column II
|
A. Phosphofructokinase |
1. Redox reaction |
|
B. Enolase |
2. Phosphoryl shift |
|
C. Phosphoglycerate mutase |
3. Dehydration |
|
D. Glyceraldehyde 3 Phosphate dehydrogenase |
4. Phosphoryl transfer |
#Question id: 640
#Section 2: General Biology
The data in the table above were collected for an enzyme-catalyzed reaction. The Km for this enzyme is approximately
#Question id: 641
#Section 2: General Biology
Which of the following does NOT describe a mechanism that cells use to regulate enzyme activities?
A. Cells control enzyme activity by phosphorylation and dephosphorylation.
B. Cells control enzyme activity by the binding of small molecules.
C. Cells control the rates of diffusion of substrates to enzymes.
D. Cells control the rates of enzyme degradation.
E. Cells control the rates of enzyme synthesis.
F. Cells control the targeting of enzymes to specific organelles.