What type of chemotherapeutic agent alters the function of cells by replacing a hydrogen atom of a molecule?

What type of chemotherapeutic agent alters the function of cells by replacing a hydrogen atom of a molecule?

a.
Plant alkaloids
b.
Antimetabolites
c.
Alkylating agents
d.
Antitumor antibiotics

ANS: C

Alkylating agents replace a hydrogen atom with an alkyl group. The irreversible combination of alkyl groups with nucleotide chains, particularly deoxyribonucleic acid (DNA), causes unbalanced growth of unaffected cell constituents so that the cell eventually dies. Plant alkaloids arrest the cell in metaphase by binding to proteins needed for spindle formation. Antimetabolites resemble essential metabolic elements needed for growth but are different enough to block further DNA synthesis. Antitumor antibiotics are natural substances that interfere with cell division by reacting with DNA in such a way as to prevent further replication of DNA and transcription of ribonucleic acid (RNA).