Question

sulfhydryl functional groups can interact together to form disulfide bridges to stabilize a protein’s shape. an increase in which amino acid, shown in the table above, would result in a more stable protein? threonine cysteine methionine histidine

Explanation:

Disulfide bridges in proteins are formed by the oxidation of the sulfhydryl groups (-SH) of cysteine residues. Cysteine is the only amino acid among the options with a sulfhydryl group in its side chain, so increasing cysteine would allow more disulfide bridges to form, stabilizing the protein. Threonine has a hydroxyl group, methionine has a thioether group (no free -SH), and histidine has an imidazole group, none of which can form disulfide bridges.

Answer:

Cysteine (the option corresponding to Cysteine among the given choices)