1.) Protein kinases are involved in
A) the digestion of drugs to potentially toxic byproducts.
B) the degradation of enzymes to the component amino acids.
C) the phosphorylation of a wide variety of proteins.
D) the metabolism of drugs to water soluble compounds.
E) the cleavage of peptide bonds.
2.) Which of the following is triggered by the binding of glucose-6-phosphate to glycogen phosphorylase?
A) The protein changes from its T form to its R form.
B) The protein changes from its R form to its T form.
C) The protein becomes dephosphorylated.
D) It catalyzes the addition of a phosphate group to AMP.
E) It catalyzes the addition of a phosphate group to Ser-14.
3.) Which of the following amino acid residues are often involved in acid-base in enzyme-catalyzed reactions?
A) Histidine, aspartate, serine, and cysteine
B) Serine, tyrosine, arginine, and cysteine
C) Glutamine, asparagine, lysine, and tyrosine
D) Histidine, aspartate, lysine, and serine
E) Histidine, aspartate, glutamate, arginine, and lysine
1.) Protein kinases are involved in
A) the digestion of drugs to potentially toxic byproducts.
B) the degradation of enzymes to the component amino acids.
C) the phosphorylation of a wide variety of proteins.
D) the metabolism of drugs to water soluble compounds.
E) the cleavage of peptide bonds.
2.) Which of the following is triggered by the binding of glucose-6-phosphate to glycogen phosphorylase?
A) The protein changes from its T form to its R form.
B) The protein changes from its R form to its T form.
C) The protein becomes dephosphorylated.
D) It catalyzes the addition of a phosphate group to AMP.
E) It catalyzes the addition of a phosphate group to Ser-14.
3.) Which of the following amino acid residues are often involved in acid-base in enzyme-catalyzed reactions?
A) Histidine, aspartate, serine, and cysteine
B) Serine, tyrosine, arginine, and cysteine
C) Glutamine, asparagine, lysine, and tyrosine
D) Histidine, aspartate, lysine, and serine
E) Histidine, aspartate, glutamate, arginine, and lysine
Related textbook solutions
Related questions
| Amino Acid | M.W. g/mol | pKa for side chain |
| Alanine | 89.1 | |
| Arginine | 174.2 | 12.48 |
| Asparagine | 132.1 | |
| Aspartate | 133.1 | 3.90 |
| Cysteine | 121.1 | 8.37 |
| Glycine | 75.0 | |
| Glutamate | 147.1 | 4.07 |
| Glutamine | 146.1 | |
| Histidine | 155.1 | 6.04 |
| Isoleucine | 131.2 | |
| Leucine | 131.2 | |
| Lysine | 146.2 | 10.54 |
| Methionine | 149.2 | |
| Proline | 115.1 | |
| Phenylalanine | 165.2 | |
| Serine | 105.1 | |
| Threonine | 119.1 | |
| Tryptophan | 204.2 | |
| Tyrosine | 181.2 | 10.46 |
| Valine | 117.1 |
Take a look at your pKa table for the amino acids. It turns out that when these side chains are in a protein, they can have very different pKa values. Explain the following observations:
a. In the enzyme medium chain acyl-CoA dehydrogenase (b-oxidation of fatty acids), E376 has a measured pKa ~ 8.0. It is found in a very hydrophobic environment. What could account for it elevated pKa?
b. For the enzyme aconitase (Krebbâs Cycle), a catalytic serine is known to have a pKa ~ 8. What kind of factors could account for this decrease in pKa?
