An enzyme is found to have maximum activity in a pH range of 6 to 8. It is inactive below pH 3. It is also found that glutamate and serine residues are present at the active site. The mutations of these residues show the following results. Select ALL statements that are consistent with the experimental results. When serine is mutated to alanine, the mutant enzyme is fully active with maximum activity at pH 6 to 8. When glutamate is mutated to alanine, the mutant enzyme is inactive at all pH. The pKa of the side chain of glutamate is 4.25. Glutamate is required for catalysis at pH 6 to 8. Serine is not required for catalysis at pH 6 to 8. Glutamate must be protonated for catalysis at pH 6 to 8. Glutamate must be deprotonated for catalysis at pH 6 to 8. Both serine and glutamate are required for catalysis at pH 6 to 8.
Enzyme kinetics
In biochemistry, enzymes are proteins that act as biological catalysts. Catalysis is the addition of a catalyst to a chemical reaction to speed up the pace of the reaction. Catalysis can be categorized as either homogeneous or heterogeneous, depending on whether the catalysts are distributed in the same phase as that of the reactants. Enzymes are an essential part of the cell because, without them, many organic processes would slow down and thus will affect the processes that are important for cell survival and sustenance.
Regulation of Enzymes
A substance that acts as a catalyst to regulate the reaction rate in the living organism's metabolic pathways without itself getting altered is an enzyme. Most of the biological reactions and metabolic pathways in the living systems are carried out by enzymes. They are specific for their works and work in particular conditions. It maintains the best possible rate of reaction in the most stable state. The enzymes have distinct properties as they can proceed with the reaction in any direction, their particular binding sites, pH specificity, temperature specificity required in very few amounts.
An enzyme is found to have maximum activity in a pH range of 6 to 8. It is inactive below pH 3. It is also found that glutamate and serine residues are present at the active site. The mutations of these residues show the following results. Select ALL statements that are consistent with the experimental results.
- When serine is mutated to alanine, the mutant enzyme is fully active with maximum activity at pH 6 to 8.
- When glutamate is mutated to alanine, the mutant enzyme is inactive at all pH. The pKa of the side chain of glutamate is 4.25.
|
|
Glutamate is required for catalysis at pH 6 to 8. |
|
|
Serine is not required for catalysis at pH 6 to 8. |
|
|
Glutamate must be protonated for catalysis at pH 6 to 8. |
|
|
Glutamate must be deprotonated for catalysis at pH 6 to 8. |
|
|
Both serine and glutamate are required for catalysis at pH 6 to 8. |
Step by step
Solved in 2 steps
