Question

figure 1 shows three amino acids that are part of a polypeptide chain. figure 2 shows the same section of the chain after a mutation has occurred. how might this change affect the structure and function of the protein?

Explanation:

Amino - acid changes can impact protein structure and function. Cysteine has a sulfhydryl group ($-SH$) which can form disulfide bonds, important for tertiary and quaternary structure. Valine has a non - polar side chain. The substitution of cysteine with valine may disrupt disulfide bond formation, altering the protein's three - dimensional shape. This can change the protein's active site (if it's an enzyme) or its binding sites, potentially impairing its function.

Answer:

The substitution of cysteine with valine may disrupt disulfide bond formation, altering the protein's three - dimensional structure and potentially impairing its function.