Question

In all enzymes the active site A. contains the substrate binding site. B. is contiguous with the substrate binding site in the primary sequence. C. lies in a region of the primary sequence distant from the substrate binding site. D. contains a metal ion as a prosthetic group. E. contains the amino acid side chains involved in catalyzing the reaction.

Short answer

Answer: A. contains the substrate binding site and E. contains the amino acid side chains involved in catalyzing the reaction.

Step-by-step solution

Understand enzyme structure and active site function

In order to understand the properties of enzyme active sites, it's important to remember that enzymes are proteins with a specific 3-dimensional shape, which allows them to catalyze biochemical reactions. The active site of an enzyme is the region where the reaction occurs, and it is formed by a specific arrangement of amino acid residues.

Evaluate each statement for correctness

Now, let's analyze each statement and determine if it is true for the active site of all enzymes: A. contains the substrate binding site. B. is contiguous with the substrate binding site in the primary sequence. C. lies in a region of the primary sequence distant from the substrate binding site. D. contains a metal ion as a prosthetic group. E. contains the amino acid side chains involved in catalyzing the reaction.

Choose the correct statement

Evaluating each of the given statements, we can determine the correct answer: A. True. The active site contains the substrate binding site, where the enzyme interacts with its substrate. B. False. The active site may not be contiguous with the substrate binding site in the primary sequence. The correct formation of the active site depends on the folding of the protein, which brings the specific amino acid residues, possibly distant in the primary sequence, together in 3D space. C. False. The statement contradicts statement A, which is true. D. False. Although some enzymes have metal ions as prosthetic groups, it is not a universal feature of all enzymes. E. True. The active site consists of specific amino acid side chains that play a role in the catalytic reaction.

Final answer

Based on the analysis, there are two correct statements: A and E. Therefore, the correct answer is: A. contains the substrate binding site. E. contains the amino acid side chains involved in catalyzing the reaction.