The human stomach secretes an enzyme known as pepsin. this enzyme breaks down proteins into smaller chemical molecules called peptides. if pepsin was mixed in a laboratory with sugar molecules like glucose, what is the most likely result? a) pepsin will break down glucose molecules into simpler substances. b) pepsin will react with glucose only if the necessary rna molecules are present. c) pepsin will probably not react with the sugar glucose since it is an enzyme that breaks down proteins. d) pepsin will probably not react with glucose since the activity of enzymes is limited to the human body.