Enzymes as Biological Catalysts Flashcards

All 7 cards in this deck

What is a biological catalyst?

A substance (an enzyme) that speeds up the rate of a reaction in a living organism without being used up itself.

What are proteins broken down into by a protease?

Amino acids.

What is starch broken down into by amylase (a carbohydrase)?

Sugars (such as maltose) — the bonds between the glucose units in the starch polymer are broken.

What are lipids broken down into by lipase?

Fatty acids and glycerol — the fatty acids make the mixture more acidic, lowering its pH.

True or false? Enzymes only break large molecules down; they are not needed to build large molecules.

False. Enzymes also catalyse synthesis reactions, joining small molecules to make carbohydrates, proteins and lipids.

In an investigation, one tube contains starch solution with distilled water instead of amylase. Give one reason this tube is included.

It is a control — to check that starch does not break down into sugars without amylase.

Which enzyme joins glucose molecules together to make glycogen?

Glycogen synthase. Glycogen is a store of energy in animals.