Exercise 9 Endo/Exo Enzymes - PICS

Amylase — Positive (+)

Organism produced amylase; starch digested

Amylase — Negative (−)

Does not produce amylase; does not digest starch.

Casease — Positive (+)

Organism produced casease. casease; digests casein.

Casease — Negative (−)

Does not produce casease; does not digest casein.

Gelatinase — Positive (+)

Organism produced gelatinase; gelatin digested

Gelatinase — Negative (−)

Does not produce gelatinase; does not digest gelatin.

Lipase — Positive (+)

Organism produced lipase; Tributyrin digested.

Lipase — Negative (−)

Organism did not produce lipase. Tributyrin intact.

Catalase — Positive (+)

Organism produced catalase. Degradation of H₂O

Catalase — Negative (−)

Does not produce catalase; does not break down hydrogen peroxide.

Oxidase — Positive (+)

Organism produced oxidase. Oxidase substrate has been reduced.

Oxidase — Negative (−)

Does not produce oxidase.

What is an enzyme?

A biological catalyst (protein) that accelerates biochemical reactions without being consumed in the process.

What is an endoenzyme?

An enzyme that operates within the cell.

What is an exoenzyme?

An enzyme that is secreted outside the cell to catalyze reactions in the external environment.

Which are the EXOenzymes in the practical?

Amylase,casease, gelatinease and lipase

Which are the ENDOenzymes in the practical?

Catalase and oxidase

Amylase — Medium, substrate, product and reagent:

Starch agar, starch, glucose, iodine

Casease— Medium, substrate, product and reagent:

Casein agar, casein, amino acids, none.

Gelatinase— Medium, substrate, product and reagent

Gelatin agar, gelatin, amino acids, none.

Lipase— Medium, substrate, product and reagent

Tributyrin agar, tributyrin, fatty acids, none.

Catalase— Medium, substrate, product and reagent

Nutrient agar, hydrogen peroxide, water and oxygen, hydogen peroxide

Oxidase— Medium, substrate, product and reagent

Nutrient agar, oxidase substrate, reduced oxidase substrate, oxidized substrate.