Question

Amino acids have a common basic structure that includes four parts. Three of the parts are a central alpha carbon, a carboxyl group, and a hydrogen atom. What is the fourth part?

A) oxygen
B) nitrogen
C) amino group
D) side chain

Answer 1

The fourth part of an amino acid's structure, distinct from the central alpha carbon, carboxyl group, and hydrogen atom, is the d. side chain or R group. This side chain is unique to each amino acid, influencing their individual properties and the proteins they form.

Step-by-step explanation:

Amino acids have a common basic structure that includes four parts: a central alpha carbon, a carboxyl group, a hydrogen atom, and a fourth part, which is the d. side chain or R group. Unlike the other three components that are consistent across all amino acids, the R group varies and is unique to each amino acid.

This varying side chain is what determines the distinct properties of each amino acid, and thus affects the structure and function of proteins they compose.