Gene expression can occur at several points along the pathway from dna to rna to proteins. in one example of gene expression, the protein insulin must be trimmed to a smaller size. how is this is an example of gene expression

2: C, I don't think insulin gene expression is regulated by the amount of trimmed/untrimmed insulin within the cell. Other pathways are involved in that function. Insulin simply isnt usable by the body until it has been properly processed within the cell.

3: D, This can happen in cancer.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.

a covalent bond, specfically triple bond