Do NowQ1. Mammals need food for energy. Give two other reasons why food is needed.

Q2. Explain why having a bowl of cereal in the morning is better than having a can of energy drink.

Q3. Explain why eating lots of vegetables is very important to prevent constipation.

Why Nutrients are neededMammals are made up of many

cells and those cells need nutrients for:

1. Energy – for all the chemical reactions which take place in the cells

2. Growth – make more cells3. Repair – replace damaged cells

On your exercise book:• Write down seven foods

containing high amounts of carbohydrates

• Write down five foods containing high amounts of lipids

• Write down five foods containing high amounts of proteins

The three classes of food that mammals consume to obtain nutrients are:

•Carbohydrates•Lipids

•Proteins

CarbohydratesCarbohydrates are starch and cellulose.• Starch is a very very long

molecule, made of many tiny units called glucose molecules. Glucose is commonly known as sugar.

• Cellulose is also a very long molecule made of glucose molecules but it cannot be digested!

Arrange these foods in order of increasing amount of energy.

• A banana• A slice of pepperoni pizza• A large cookie (Cookie Time)• A cup of milk• A slice of bread• A BigMac burger from

McDonalds• A scoop of chips from Fish n’

Chips

1. Circle five foods on the list that have the highest amount of energy.

2. Circle (in a different colour) five foods on the list that have the lowest amount of energy.

LipidsLipids are fats and oils, made up of glycerol and fatty acids.Lipids have three times more energy than carbohydrates, but are much harder to break down.

ProteinsProtein molecules are made up of many amino acids.Proteins contain little amount of energy but they are needed for growth and repairing of the body, as they are the building blocks of cells.

The body also needs…• Vitamins & Minerals• Water

Name: Beriberi

SymtomsStomach troublesMuscle paralysisDeath

CauseLack of Vitamin D

Name: Scurvy

SymtomsThe gums and nose bleedInternal bleeding may also occur

CauseLack of Vitamin C

Name: Rickets

SymtomsBones become very soft and bent

CauseLack of Vitamin DLack of Calcium