Final answer:
The linkage that combines two amino acids is called a peptide bond, an amide bond formed during a dehydration synthesis reaction that releases water.
Step-by-step explanation:
The linkage made that combines two amino acids is called a peptide bond. This bond is formed during a dehydration synthesis reaction, where the carboxyl group of one amino acid links to the amino group of the incoming amino acid. In this process, a molecule of water is released, and the resulting peptide bond is an amide type of chemical bond. Thus, when referring to the connection between amino acids, a peptide bond is the correct answer, which is option (a) Peptide bond.
Peptide bonds are fundamental to forming peptides, polypeptides, or proteins, as they join the building blocks of proteins together. These bonds are crucial for the structure and function of proteins, which play diverse roles in biological processes within the body.