Answer:
An amino acid
Step-by-step explanation:
Amino Acid:
- An amino acid, the building block of a protein, is a biomolecule that contains the amino (-NH3+) and carboxylate (-COO−) groups.
- Amino acids also contain an organic R- group that defines the properties of the amino acid.
- R-groups classify amino acids into different categories such as non-polar, polar, acidic and basic.
- The carboxyl group of an amino acid combines with the amino group of another amino acid to form a covalent amide bond or a peptide bond.
- Amino acids form polypeptides by the formation of peptide bonds.