Question

The enzyme known as alcohol dehydrogenase is capable of oxidizing ethanol, methanol and other hydroxyl group containing organic compounds into their corresponding aldehydes. Such an enzyme with ___ catalyzes the reaction of structurally related substances. Select one:

a. absolute specificity

b. relative specificity

c. stereospecificity

d. no specificity

Answer 1

OPTION B. Specificity of enzymes can be classified into absolute specificity, linkage specificity, group specificity and stereospecificity.

Absolute specificity is when an enzyme catalyzes only one reaction, with one substrate only.

Group specificity is when an enzyme acts on molecules with only one specific functional group regardless of the other parts of the molecule.

Linkage specificity is when an enzyme acts on molecules containing a particular bond regardless of the rest of the molecule.

Stereospecificity is when an enzyme acts only on a certain stereoisomer.

Of these, group specificity and linkage specificity are classified as relative specificity due to the flexibility allowed in the other parts of the substrate.

Alcohol dehydrogenase is not specific to only one alcohol molecule but oxidizes a variety of alcohols, making it specific to the hydroxyl group in a molecule rather than being specific to a particular molecule. So, the enzyme exhibits relative specificity.