Chapter 3 - 'Food'

Question 1

Why do organisms need food? (3)

Answer 1

Nutrients are necessary for:

1. source of energy
2. make chemical reactions needed for metabolic reactions
3. Raw materials for the growth and repair of structures in organism

Question 2

Name 6 of the 14 elements needed for living things

Answer 2

Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Sulfur (S)

Question 3

Explain the term ‘Biomolecules’

Answer 3

Chemicals that are made inside a living thing (also called biochemicals. contain carbon.)

Question 4

Name 4 major types of Biomolecules

Answer 4

Carbohydrates
Lipids
Proteins
Vitamins

Question 5

Name the 3 types of carbohydrates and what they are

Answer 5

Monosaccharide - one single sugar unit

Disaccharide - two sugar units

Polysaccharide - multiple sugar units

Question 6

What do monosaccharides (and disaccharides) taste like and name one characteristic

Answer 6

monosaccharides (and disaccharides) are sweet to taste and are soluble in water.

Question 7

what is the main chemical from which living things get their energy? (monosaccharide)

where is this found in diet

Answer 7

glucose

sweets, chocolate, fruit and soft drinks

Question 8

What monosaccharide has the same formula as glucose but is arranged differently? Compare the taste

Answer 8

Fructose. Much sweeter than glucose. Common in fruits.

Question 9

What type of carbohydrates are maltose (found in germinating seeds) and sucrose (table sugar)

Answer 9

Disaccharides

Question 10

Give one characteristic of Polysaccharides and describe taste

Answer 10

Polysaccharides are insoluble or only slightly soluble in water.

They are NOT sweet tasting

Question 11

Do polysaccharides have large or small molecules

Answer 11

large

Question 12

Starch, cellulose and glycogen are all examples of what type of carbohydrate?

Answer 12

Polysaccharide

Question 13

What is another name for starch

Where can it be found in our diet

State whether is it easy or not to digest

Answer 13

Amylose

Bread, potatoes, rice, pasta

Easy to digest (only necessary to break 2 bonds)

Question 14

Cellulose is composed of many _______ molecules linked together.

Where can it be found in our diet

Where is it used in the structure of cell

State whether is it easy or not to digest

Answer 14

Cellulose is composed of many GLUCOSE molecules linked together.

fibre-high foods

Cell wall (very strong)

Very difficult to digest (we use it as roughage or fibre in our diet)

Question 15

Glycogen is a complex polysaccharide. Where do animals store glycogen

Answer 15

Animals store glycogen in their liver and muscles.