Question

Which one of the following is the correct match of digestive enzyme and substrate?
A. Lactose-Renin
B. Starch-Maltose
C. Fat-Steapsin
D. Casein-Trypsin

Answer 1

Hint: We need to know about digestive enzymes and the substrates they catalyze. Enzymes use substrates and convert them into their desired products. These enzymes are nothing but complex protein molecules. Digestive enzymes are a collection of enzymes that help the body absorb polymeric macromolecules by breaking them down into their smaller building parts.

Complete answer:
Digestive enzymes can be found in the digestive tracts of animals and carnivorous plants, where they help with food digestion, as well as inside cells, particularly in lysosomes, where they help sustain cellular life. The saliva secreted by the salivary glands, the secretions of cells lining the stomach, the pancreatic juice secreted by pancreatic exocrine cells, and the secretions of cells lining the small and large intestines all include digestive enzymes of various specificities.
Steapsin is a digestive enzyme that catalyses the hydrolysis of triglycerides to fatty acids and glycerol. It is present in pancreatic juice and belongs to the lipases family of digestive enzymes. As a result, fats-steapsin is the ideal digestive enzyme for this substrate.
Therefore, the correct option is option C.

Additional information:
Renin is a protease which is secreted by kidneys which cannot use lactose as substrate which is a carbohydrate. Hence, option A is incorrect.
Starch and maltose are sugars and none of them are digestive enzymes. Hence, option B is incorrect.
Casein is a milk protein which is digested by chymotrypsin and not trypsin. Hence, option D is incorrect.

Note:
Note that the enzyme lipase is also known as steapsin. This is the name given to the lipase enzyme found in pancreatic juice. This is one of the digestive enzymes that aids in the digestion of fats. Fats are broken down into fatty acids and glycerol by this enzyme. The free fatty acids can then be absorbed into the liver and kidneys, where they can be converted to glyceraldehyde 3-phosphate, a component of glycolysis, and eventually into ATP via the citric acid cycle. Fatty acids that aren't consumed for energy can then get through the intestinal barrier and be repackaged as fatty tissue.