A Level Biology Practice Exam

In what form do amino acids link to form proteins?

1. Pebble structures

2. Complex carbohydrates

3. Peptide bonds

4. Fatty acid chains

The correct answer is: Peptide bonds

Amino acids link to form proteins through peptide bonds. This type of bond specifically forms between the carboxyl group of one amino acid and the amino group of another, resulting in a covalent linkage that creates a dipeptide. As more amino acids join in this manner, they build a polypeptide chain, which then folds into the functional protein. The process of protein synthesis involves ribosomes translating mRNA sequences, where the sequence of amino acids is determined by the genetic code. The formation of peptide bonds is essential for the creation of proteins, as it allows the linear sequence of amino acids to connect through these strong covalent bonds, leading to the intricate structures and functions of proteins within living organisms. Other options provided, such as pebbles, complex carbohydrates, and fatty acids, do not relate to the method of linkage in protein formation, as they pertain to different biological structures and functions.