Bio Revision B5 Biological Molecules

Small molecules are used as the basic units in the synthesis of large food molecules. Which statement is correct?

• Amino acids are basic units of carbohydrates.

• Fatty acids are basic units of glycogen.

• Glycerol is a basic unit of oils.

• Simple sugar is a basic unit of protein.

When a substance is added to meat, amino acids are produced. What is this substance?

• a hormone

• an enzyme

• an oil

• water

The diagram shows part of a protein molecule. What does X represent?

• amino acid

• fatty acid

• glycerol

• sugar

The diagram represents a protein molecule. What do the small circles represent?

• amino acids

• fatty acids

• glycerol

• simple sugars

Which nutrient produces a purple colour when mixed with biuret solution?

• fat

• protein

• reducing sugar

• starch

Which simple molecules are the basic units of protein?

• amino acids

• fatty acids

• sugars

• vitamins

Which food-testing reagent shows a positive result when it turns from blue to purple?

• Benedict’s solution

• biuret reagent

• ethanol

• iodine solution

The diagram shows two food tests carried out on solution X. Which nutrients are present in solution X?

• protein and starch

• protein and sugar

• starch and fat

• starch and sugar

The diagram shows two food molecules before and after they have been digested by enzymes. What identifies the products of fat digestion?

• P and R

• P and S

• Q and R

• Q and S

The graphs show the quantities of selected vitamins and mineral ions in four foods. Which food is the richest source of the vitamin or mineral ions essential for the transport of oxygen by the blood?

• beans

• egg

• fish

• fruit