Subject: Biology

Title:

Name Duty

Cheung Wai Yee Author of p.1 – p.9

Fung Ying Chi Author of p.10 – p.18

Leung Shuk Ming Author of p.19 – p.25

Duty List:

Introduction:

1.1. Target Audience:Target Audience:

F.3 students with average ability.F.3 students with average ability.

2. How to use these slides?2. How to use these slides?

This is a teaching material for lecturing. These slides will be accompanied with food labels and some food samples.

Objectives:

Balanced dietsDeficiency diseases

Functions of different food substances

Function of food Types of food substances

We should know……

What is Food?

• Food is something that living organisms take into their bodies to provide energy and to help them to develop and to live.

• The food for Human is made of SEVEN components. These components are called food substances.

Seven Food Substances

Food Substances

Carbohydrates

Proteins

Water

Dietary Fibre Minerals

Vitamins

Fats

Functions of Food1. Provide Energy

2. Growth and Repair

3. Keep Healthy

Carbohydrates

Food source:

Functions of carbohydrates: Supply energy

Food reserve Structural materials

Proteins

Food source :

Functions of proteins :

For growth and repair

Fats

Food source:

Functions of fat:

Supply energy Food reserve

Heat insulator

Structural material of cell membrane

Vitamins

Examples of vitamins:

Vitamin

Vitamin

Vitamin

A

C

D

Functions of vitamins:

To keep us healthy

Minerals

Examples of minerals:

Calcium

iron

Functions of minerals: To keep us healthy

Dietary fibres

Food source:

Functions of dietary fibres:

To prevent constipation

Water

Functions of water: Main component of cells

Transport of dissolved materials

Deficiency diseases

- Lack of certain vitamin and mineral will cause deficiency disease

Food substancesFood substances Deficiency diseaseDeficiency disease

Vitamin A Night blindness

Vitamin C Scurvy

Vitamin D and Calcium

Rickets

iron Anaemia

Night blindness

- Vitamin A is needed for the formation of pigment in retina which is necessary for night

vision. Therefore lack of vitamin causes night blindness

Scurvy

- Lack of vitamin C would result in poor healing of wounds and bleeding gum

Calcium is need for the formation of bones and teeth.

Vitamin D helps the absorption of calcium.

Lack of vitamin D and calcium would result in Ricketsi.e. bones becomes soft and weak

Rickets

Anaemia- Iron is needed for the formation of haemoglobin in

red blood cells.- Lack of iron causes anaemia.

Balanced Diet- A diet which contains all the seven food

substances in right amount.

- The amount of the food substances for each individual depended on:

Sex

Occupation

Age

Physical activities

Reversion Quiz

1. How many food substances are contained in human food?

A.A.FiveFive

B.B. SixSix

C.C. SevenSeven

2. Which of the following food substances promote growth?

Reversion Quiz

A.A. ProteinsProteins

B.B. CarbohydratesCarbohydrates

C.C. FatsFats

Reversion Quiz

3. Lack of Iron will cause

A.A. RicketsRickets

B.B. AnaemiaAnaemia

C.C. ScurvyScurvy

D.D. OverweightOverweight

Reversion Quiz

4. Meat contains noA.A. FatsFats

B.B. WaterWater

C.C. Dietary FibreDietary Fibre

D.D. ProteinsProteins