B1.3.1 - Carbohydrates, Proteins and Lipids

Question 1

Why do you need food?

Answer 1

Foods rich in carbohydrates and fats provide you with energy to move and stay alive.
Protein-rich foods are used for the growth and repair of body tissues
You need small amounts of vitamins and minerals to remain healthy

Question 2

Metabolic rate

Answer 2

The amount of energy expanded by tht organism in a given time period
The speed at which chemical reactions in your cells transfer energy from its chemical stores in food
The higher your metabolic rate, the more food you eat.

Question 3

Carbohydrates

Answer 3

Some carbohydrates are polymers - they are made from smaller carbohydrate molecules such as sugars.
There are different types of sugars, you use sucrose for cakes, lactose in milk, etc.
Starch is an example of a carbohydrate polymer, it is synthesised from glucose monomers.
Amylase breaks down starch

Question 4

Proteins

Answer 4

Proteins are polymers - they are formed from amino acids.
There are about 20 different amino acids
The order in which the amino acids are joined determines the protein that is synthesised.
Protease enzymes break down proteins into amino acids.

Question 5

Lipids

Answer 5

Lipids are fats and oils that you eat.
Good store of energy
Some animals, such as seals, use them for insulation and buoyancy
Lipids are synthesised from three fatty acid molecules and a glycerol molecule.
Lipase enzymes break down lipids into fatty acids and glycerol

Question 6

What happens after you eat the food?

Answer 6

The food molecules are fully digested into soluble glucose, amino acids, fatty acids and glycerol. They are then absorbed into your bloodstream and travel to the cells that need them.