Nutrition and Digestion - Revision

7/28/2019 Nutrition and Digestion - Revision

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Nutrition and Digestion

Revision powerpoint



Characteristics of living things

All living things have share seven common characteristics.

Each letter in the phrase MRS GREN gives

you the first letter of one of the life

processes.

Movement

Respiration

Sensitivity

Reproduction

Growth

Excretion

Nutrition

If something does not perform all of the seven

life processes then it is not alive. Which of the

seven life processes can a car do?



Nutrition

Why do we need to eat food?

To gain energy to carry out the life processes.

To gain essential nutrients so we can stay healthy and grow.

Which foods do we need to eat for a balanced diet?

Carbohydrates

Proteins

Fats and oils

Vitamins

Minerals

Fibre

Water



Carbohydrates

CARBOHYDRATES supply our bodies with ENERGY. The

energy from carbohydrates is released during the process of

RESPIRATION.

Which types of foods contain carbohydrates?

Bread

Potatoes

Rice

Pasta

Cakes

Jam

Sweets



Proteins

PROTEINS supply our bodies with the BUILDING BLOCKS

FOR GROWTH.

Which types of foods contain proteins?

Fish

Meat

Milk

Eggs

Cheese

Butter

Beans



Fats and Oils

FATS and OILS supply our bodies with TWICE AS MUCH

ENERGY as carbohydrates. We can also STORE FOOD as fat.

Which types of foods contain fats and oils?

Butter

Cakes

Lard

Vegetable oil

Crisps

Chips

Meat



Exercise 2: VitaminsVITAMINS are substances which are essential in our diet to

help chemical reactions in our body. There are many different

types of vitamins. Use a textbook or other source to complete

the table below:

Vitamin Found Deficiency

A

C

D

Carrots, liver,

green

vegetables

Can cause

poor night

sight

Green

vegetables,oranges,

blackcurrants

Can causeSCURVY

Fish & eggsCan cause

RICKETS



Exercise 3: Minerals

MINERALS are substances which are essential in our diet for

healthy growth. There are many different types of minerals.

Use a textbook or other source to complete the table below:

Mineral Found Used for

Iron

Calcium

Liver, eggs,

cabbage

Making teeth

and bones

Vegetables,

milk, cheese

Making blood



Exercise 5: Food Tests

1. Complete the table below.

Test Food tested

for:

End

colour:

Iodine _______ Black

_______

Reagent

Protein Purple

Benedict’s

Reagent

Glucose _______

Starch

Biuret

Orange



The Digestive System

Mouth

Oesophagus

Stomach

Small intestine

Large intestine

Rectum

Anus

Liver

Pancreas



Food and Digestion

The digestive system has two roles:

Break food up into smaller pieces.

Absorb food into the bloodstream.

The mouth

In the mouth the food is BROKEN UP into small pieces by the

TEETH. At the same time SALIVA is added. This moistens

the food - making it easier to swallow - and begins the

digestion of carbohydrates using the enzyme AMYLASE.

The oesophagus

After the mouth, food passes along the OESOPHAGUS to the

STOMACH.



The Stomach

When the food enters the stomach several things happen:

The stomach acts like a cement mixer and CHURNS the food.

ENZYMES are added to begin the chemical break up of PROTEINS.

HYDROCHLORIC ACID is added as the enzymes in the stomach

work best in ACIDIC CONDITIONS.

The acid also KILLS ANY BACTERIA.

ENZYMES are chemicals that SPEED UP the chemical breakdown of food in our bodies.

What colour would stomach acid turn litmus paper? RED



The Intestines

The food passes from the stomach into the SMALLINTESTINE. Here, more ENZYMES are added to help

chemically break down the food and the food is ABSORBED

through the walls of the small intestine.

After passing through the small intestine the UNDIGESTED

FOOD moves into the LARGE INTESTINE. In the large

intestine WATER IS ABSORBED.

At the end of the large intestine the undigested food is

STORED in the RECTUM before it is removed from the body

through the ANUS.

The LIVER makes BILE - as this is alkaline - the small

intestine works best in alkaline conditions. The PANCREAS

makes enzymes to aid in the chemical break up of the food.



Small Intestine Adaptations

The small intestine is ADAPTED to absorbing food efficientlyin several ways:

A villus

It is MOIST as only soluble food can be absorbed.

It has VERY THIN WALLS so the food can be more easily

absorbed.

It is covered in millions of

finger-like projections called

VILLI. This INCREASES

THE SURFACE AREA of thesmall intestine for absorption.

Each villus has a DENSE CAPILLARY NETWORK so that the

food is more easily absorbed into the bloodstream.



Exercise 6: Label the Diagram

Mouth

Oesophagus

Stomach

Small intestine

Large intestine

Rectum

Anus

Liver

Pancreas

A.______

B.___________

C.______

D.____________

E.____________

F._______

G.________

H.______

I._____

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Nutrition and Digestion - Revision