Biological Molecules Sec3

Small molecules are used as the basic units in the synthesis of large food molecules.

Which statement is correct?

• 1. Amino acids are basic units of carbohydrates.

• 1. Fatty acids are basic units of glycogen.

• 1. Glycerol is a basic unit of oils.

• 1. 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

Four different foods were tested for their composition.
The results are shown in the table.
Which food contains protein but not reducing sugar or starch?

• A

• B

• C

• D

What are the smaller basic units of starch and glycogen molecules?

• A

• B

• C

• D

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

• amino acids

• fatty acids

• glycerol

• simple sugars

Which row shows the elements and basic units that are used in the construction of large food molecules?

• A

• B

• C

• D

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