Chapter 4: Biological molecules

Question 1

What are the chemical elements that make up carbohydrates, fats, and proteins?

Answer 1

1. C, H, O
2. C, H, O
3. C, H, O, N

Question 2

What are the simplest types of carbohydrate?

Answer 2

Monosaccharides, or sugars, e.g. glucose

Question 3

What are large carbohydrate molecules made of, and examples?

Answer 3

Glucose, e.g. disaccharides such as maltose and sucrose, and polysaccharides such as starch, glycogen, and cellulose

Question 4

What are fats made up of?

Answer 4

Fatty acids and glycerol

Question 5

What are proteins made up of?

Answer 5

Amino acids

Question 6

What is iodine solution?

Answer 6

A brown solution that turns blue-black when mixed with starch

Question 7

What is Benedict’s solution?

Answer 7

A blue liquid that turns orange-red when heated with reducing sugars

Question 8

What is biuret reagent?

Answer 8

A blue solution that turns purple when mixed with amino acids or proteins

Question 9

What is the ethanol emulsion test?

Answer 9

A test for lipids that turns milky when positive

Question 10

What is DCPIP solution?

Answer 10

A blue solution that turns colourless in the presence of vitamin C

Question 11

Describe the structure of a DNA molecule (4 points)

Answer 11

1. 2 strands coiled together to form a double helix
2. Each strand contains chemicals called bases
3. Bonds between pairs of bases hold the strands together
4. Bases always pair up the same way, A with T, and C with G