lec 12 - catalase, amylase, oxidase

what is an exoenzyme? what does it degrade?

excreted from cells; degrades large extracellular reactions

what is a type of exoenzyme? what does it do?

amylase; it degrades starch into sugars like maltose and glucose

what reagent is amylase tested with?

lugol’s iodine

what does a positive and negative amylase test look like?

positive has starch degraded and a zone of clearing; negative has no starch degraded and no zone of clearing

what is an endoenzyme?

stays within the cells; catalyze intracellular reactions

what are examples of endoenzymes?

catalase and oxidase

what does catalase do?

detoxifies H2O2 produced during aerobic respiration

what is the catalase reaction?

H2O2 → 2 H2O + O2

what is catalase detected with

hydrogen peroxide

what does a positive and negative catalase reaction look like?

positive is bubbles since catalase is present and negative is no bubbles since catalase is not present

what is oxidase?

cytochrome oxidase is the final component in ETC for many bacteria

what is happening in the oxidase reaction?

reduced O2 ro H2O

what is oxidase tested with?

oxidase reagent

what does a positive and negative oxidase test look like?

positive goes from colorless to light pink to maroon to blue/black and negative goes from colorless to no change