What food is made of — questions

1. identify

Match each nutrient to the elements it contains.

Write the number of the matching option.

1. Carbon, hydrogen and oxygen only
2. Carbon, hydrogen, oxygen and nitrogen
3. Carbon, hydrogen and nitrogen only

• Carbohydrate: ______
• Fat or oil: ______
• Protein: ______

Nudge (only if you are stuck): Only one of the three main nutrients contains a fourth element.

2. identify

Match each large molecule to the smaller molecules it is made from.

Write the number of the matching option.

1. Glucose
2. Amino acids
3. Fatty acids and glycerol

• Starch: ______
• Glycogen: ______
• Cellulose: ______
• Protein: ______
• Fat or oil: ______

Nudge (only if you are stuck): Three of the large molecules are made from the same small sugar.

3. sequence

Put these in order of size, from the smallest to the largest.

Write the number of each step in order.

1. A carbon atom
2. A glucose molecule
3. A starch molecule

• First: ______
• Second: ______
• Last: ______

Nudge (only if you are stuck): A molecule is made of atoms, and a large molecule is made of many small molecules.

4. list

List the chemical elements that make up each of these nutrients.

(a) Carbohydrates

(b) Fats

(c) Proteins

Nudge (only if you are stuck): Three elements are in all of them. One nutrient has a fourth.

5. name

Name the smaller molecule that each of these large molecules is made from.

(a) Starch

(b) Glycogen

(c) Cellulose

(d) Protein

Nudge (only if you are stuck): Two of these four are stores of energy, one is in plant cell walls and one has about 20 kinds of unit.

6. identify

Which statement about glycogen is correct?

Circle one answer.

• It is made from glucose and is stored in the liver and muscles of animals
• It is made from amino acids and is stored in muscles
• It is made from glucose and forms plant cell walls
• It is a fat stored under the skin

Nudge (only if you are stuck): Glycogen is a store, but not a plant store.

7. identify

Which statements about a fat molecule are correct? Choose all that apply.

Tick every correct statement.

• It contains one glycerol
• It contains three fatty acids
• It is a long chain of fatty acids joined end to end
• It contains nitrogen
• It contains carbon, hydrogen and oxygen

Nudge (only if you are stuck): Look at the diagram of a fat molecule: count its parts.

8. explain

Egg white protein and the keratin in your hair are both made from the same 20 or so kinds of amino acid. Explain how they can be different proteins.

Nudge (only if you are stuck): What is different about the chain in each protein, if the units are the same kinds?

9. deduce / explain

A food scientist extracts a pure white powder from a breakfast cereal. It is known to be a carbohydrate, a fat or a protein. Analysis shows that it contains carbon, hydrogen, oxygen and nitrogen. (a) Which of the three is it? (b) Explain your answer.

(a) Nutrient

(b) Explanation

Nudge (only if you are stuck): Which of the three main nutrients is the only one with nitrogen?

10. compare / explain

Inulin is a carbohydrate stored in onions and chicory roots. Each inulin molecule is a chain of many units of a sugar called fructose. (a) Which large molecule from the reading is inulin most like in the way it is built? Explain. (b) A student says: "A fat is built the same way, as a long chain of fatty acids." Explain why the student is wrong.

(a) Most like … because …

(b) Why a fat is not a chain

Nudge (only if you are stuck): (a) Is inulin one kind of small unit repeated in a chain? (b) Count the parts in a fat molecule.