Question

Which statement is true?

• A. All proteins are enzymes, and some RNA molecules also are catalytic.

• B. Most enzymes are proteins, but some RNA molecules also are catalytic.

• C. All proteins are enzymes.

• D. All enzymes are proteins.

Answer 1

Proteins are one of the major classes of biomolecules. Amino acids are the monomers that are linked by the peptide bonding to form a polypeptide and many polypeptides join to form a protein.

The catalyst used in the chemical reactions to fasten the rate of the reaction is called an enzyme.

The molecules acting as a catalyst in the reactions is called the enzymes. There are a variety of proteins like fibrous proteins, structural proteins, transport proteins, membrane proteins, contractile proteins, antibodies, enzyme proteins, etc. All the proteins are not biocatalyst. Therefore, all proteins are not enzymes.

Hence, the options (a) and (c) are incorrect.

A molecule that fastens the rate of a biochemical reaction and works as a catalyst is known as an enzyme. The enzymes are generally proteins. Therefore, most enzymes are proteins.

Hence, option (d) is incorrect.

A ribonucleic acid enzyme (RNA enzyme) that catalyze some specific chemical reactions is known as ribozyme or catalytic RNA. They are present in the ribosome and helps in joining amino acids to form proteins.

Therefore, some RNA (ribonucleic acid) molecules are catalytic in nature and most enzymes are proteins.

Hence, option (b) is correct.