Which of the following statements about enzyme is not true?
a. enzymes work best at a specified ph
b. all enzymes have the same shape as their substrates.
c. enzymes are proteins
d. the shape of an enzyme allows it to do its job

Option (B).

Explanation:

Enzymes are the biocatalyst that has the ability to increase the rate of the biochemical reactions. They works at the specific biological temperature and pH conditions.

Different enzymes are used in different biochemical reactions. Enzymes are specific to its substrate shape. The enzymes has the shape according to its substrate. Some enzymes modify the shape of the substrate after its binding with substrate. All enzymes do not have the same shape as their substrate.

Thus, the correct answer is option (B).

b. the carbon cycle ensures living things have a source of hydrogen