The following question(s) are based on the reaction A + B ↔ C + D shown in the accompanying figure.
-You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?
A) It is probably a structural protein that is involved in cell-to-cell adhesion.
B) It is probably an enzyme that works through allosteric regulation.
C) It is probably an enzyme that works through competitive inhibition.
D) It is probably a cell membrane transport protein-like an ion channel.
E) It is probably a structural protein found in cartilage or skeletal tissue.

Question

The following question(s) are based on the reaction A + B ↔ C + D shown in the accompanying figure. 
-You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?
A) It is probably a structural protein that is involved in cell-to-cell adhesion. 
B) It is probably an enzyme that works through allosteric regulation. 
C) It is probably an enzyme that works through competitive inhibition. 
D) It is probably a cell membrane transport protein-like an ion channel. 
E) It is probably a structural protein found in cartilage or skeletal tissue.

Quizplus · Accepted Answer

The presence of two binding sites suggests that this protein is likely an enzyme that is regulated by allosteric modulation, which occurs when a regulatory molecule binds to the small site and changes the conformation of the protein to affect its activity. The large binding site is likely the active site for substrate binding and catalysis. The other answer choices are not supported by the information given.

The Following Question(s) Are Based on the Reaction a