Chapter 4 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?

• enzyme

• hormone

• oil

• water

The diagram shows part of a protein molecule.

What does X represent?

• amino acid

• fatty acid

• glycerol

• sugar

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 acid

• fatty acid

• glycerol

• simple sugar

   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

  A human cell contains a length of DNA that carries the code for making which substance?

• fat

• glycogen

• lipase

• starch

  A student set up a test-tube containing starch, water and amylase.

How could the student test whether the amylase had digested all the starch?

• Add Biuret solution.

• Add dilute hydrochloric acid.

• Add iodine solution.

• Weigh the test-tubes and contents before and after the experiment.

Water is a good solvent.

What does this mean?

• It dissolves well in many other substances.

• It flows easily through vessels.

• It is permeable to gases.

• Many substances dissolve well in it.