Michigan Barber Practice Exam

Amino acids are joined end-to-end by ______________.

1. Ionic Bonds

2. Covalent Bonds

3. Hydrogen Bonds

4. Peptide Bonds

The correct answer is: Peptide Bonds

Amino acids are joined together through a process known as dehydration synthesis, which forms a covalent bond between the carboxyl group of one amino acid and the amino group of another. This type of bond is called a peptide bond. Ionic bonds involve the electrostatic attraction between positively and negatively charged ions, and hydrogen bonds are weak interactions between a hydrogen atom and an electronegative atom. While both types of bonds may play a role in the folding and structure of proteins, they do not connect amino acids in a chain like peptide bonds do. Therefore, the correct answer is D.