BIOMG 3300 UNIT 3 Questions with Complete Solutions

ligand Correct Answer-a small molecule that binds specifically to a larger one (i.e., protein). For example, a hormone is the ligand for its specific protein receptor [a molecule bound reversibly by a protein. binding site Correct Answer-the location (crevice or pocket) on a receptor protein to which a ligand binds induced fit Correct Answer-The change in shape of the active site of an enzyme so that it binds more snugly to the substrate, induced by entry of the substrate. Renders the substrate catalytically active. Substrate Correct Answer-The reactant on which an enzyme works. catalytic (active) site Correct Answer-the ligand-binding site Why do mulitcellular organisms transport oxygen on Fe+2 incorporated into a heme group? Correct Answer-Multicellular organisms transport oxygen on Fe+2 incorporated into a heme group because the oxygen is poorly soluble in aqueous solutions; also oxygen can only diffuse in very short distances (and no amino acids can transport it, so Fe+2 it is...). However, Fe+2 promotes the formation of highly reactive oxygen species that can damage DNA, etc., so it must be bound in forms that sequester it and make it less reactive. Heme Correct Answer-A prosthe