Question

Your liver has an extra enzyme for phosphorylating glucose with a much higher Km for the glucose substrate. The existence of this different version of the enzyme with a different Km allows the liver to gain extra sugar when blood sugar is high, and is an example of _____________________.

A. covalent modification
B. isoenzymes
C. zymogens
D. allosterism

Answer 1

Answer: B

Step-by-step explanation:

Isoenzymes are different forms of the same enzyme that have slightly different structures, but perform the same biochemical reaction. These different forms of the enzyme have distinct characteristics, such as different affinities for substrates or different reaction rates. In this case, the liver has an isoenzyme of the enzyme responsible for phosphorylating glucose. This isoenzyme has a higher Km, which means it requires a higher concentration of glucose to reach half of its maximum reaction rate.