Question

carboxyl and phosphate groups are examples of ________. free radicals oxidizing agents colloids functional groups

Explanation:

Carboxyl ($-COOH$) and phosphate ($-PO_4$) are well - known functional groups in organic and biochemistry. Functional groups are specific groups of atoms within molecules that have characteristic chemical properties and reactions. Free radicals are atoms, molecules, or ions with unpaired electrons. Oxidizing agents are substances that can accept electrons from other substances. Colloids are mixtures where particles are dispersed in a medium. Carboxyl and phosphate do not fit the definitions of the first three options but are functional groups.

Answer:

D. functional groups