Chapter 2_International Science (FOOD and DIGESTION

7/29/2019 Chapter 2_International Science (FOOD and DIGESTION

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C l i c k t o e d i t M a s t e r s u b t i t l e s t y l eC h a p t e r 2

I n t e r n a t i o n a l S C I E N C E

B y : M S s u m a t h i

FOOD AND DIGESTION


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A BALANCED DIET

Contain the right proportions(amounts) ofcarbohydrates, proteins, fats, vitamins, minerals,

water and fibre

Others(Fats,oils and sweet): eat

sparingly

Meat group: protein 2-3 servings

Fruit group: vitamins,

fibre 2-4 serving

Grain group:carbohydrates 6- 11 servings

Milk group: protein3-4 servings

Vegetable group:

Vitamins, fibre3-5 servings


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CARBOHYDRATES AND PROTEIN

1. CarbohydratesInclude sugars and starchesStarches are made up of molecules of simple sugars such

as starches

Main role: To provide the _____ our bodies need tofunction

2. ProteinsMade from chains of chemicals called __________Repair damaged cells and help to build the bodyToo much or too little protein can lead to deficiency

diseases such as _____________(common in Africa)


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FATS

3. FatsMixture of molecules called _______When such mixture is ______at room temperature, it is

called a ______(margarine and butter)When it is _______ at room temperature, it is called an

_____(olive oil, canola oils)Good source of energy1 gram of fat has _____ the energy value of one gram of

carbohydrate.

Also important for keeping us ____ and protecting ourorgansToo much animal fat can result in high levels of _______ in

our blood which causes arteries to become blocked andcauses _______ and ____________.


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VITAMINS AND MINERALS

Nutrients that protect our bodies to fight ____________4) Vitamins

5) Minerals


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Fibre and Watrer

6. FibreSometimes called ________Is actually _______, a carbohydrate found in all plantsCellulose ______ be digested by human body but play role by

keeping food moving through our digestive systems whichhelps to prevent ___________ and more serious problemsuch as cancer

7. WaterHuman body is about _____% water

Necessary for transporting substances in the sweat, urine andbloodSweating cools the body when it overheatsOn overage , we need to drink 1 litres each day

(____glasses)


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THE HUMAN DIGESTIVE SYSTEM AND HOWIT WORKS

1) Mouth The mouth is the beginning of the digestive tract. Chewing breaks the food into pieces that

are more easily digested, while ______ mixes with food to begin the process ofbreaking it down into a form your body can absorb and use.

2) Throat Also called the _______, the throat is the next destination for food you've eaten. From

here, food travels to the oesophagus or swallowing tube.

3) Oesophagus The oesophagus is a muscular tube extending from the pharynx to the stomach. By means

of a series of contractions, called _________, it delivers food to the stomach.

4) Stomach

Food is mixed with __________, which are produced by stomach lining. The stomachsecretes acid and powerful enzymes that continue the process of breaking down thefood. From there the food moves to the small intestine.


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5)Small Intestine Made up of three segments, the duodenum, jejunum,

and ileum, the small intestine is a long tube looselycoiled in the abdomen (____ m long) where mostdigestion takes place. The small intestine continues

the process of breaking down food by using enzymesreleased by the pancreas and bile from the liver.Digested food is absorbed into the ______ throughthe walls of the small intestine

6) Large intestine Water, mineral salts and vitamins are absorbed from

the undigested food here. Wastes are stored in the_______, until they leave the body in the form of________.

7) Pancreas Produces ________ juice These enzymes break down

protein, fat, and carbohydrates from the food we eat.

8)Liver Produces ______ which helps to break _____ into

small pieces

9)Gallbladder _____ is stored here until it is needed


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Mechanical and Chemical Digestion

Two types of digestion take place in our bodies:

1. Mechanical digestion Food is ______ broken down into smaller pieces. Starts with the ______ and continues throughout the digestive system as

food is squeezed and pushed by various ______ in the process ofperistalsis

2. Chemical digestion Involves changing food into molecules of simpler substances, which can

dissolve in ______.

_______ juices at various places in the digestive system help this happen These digestive juices contain_________, which break down large foodmolecules into smaller ones

When digestion is complete, the food particles are small enough to passfrom intestine into blood. The blood then carries these nutrients aroundthe body to be used for energy, growth and repair of cells


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MECHANICAL DIGESTION


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CHEMICAL DIGESTION


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Different Digestive System

Digestive system of different animals are adapted to suitthe eating habits of the animals

Omnivores-eat both plant and animal foodstuffs

Front teeth(incisors) are used for ______ and bitingDo not really need to tear flesh, so _______ (side teeth)

are not well developed

Flat teeth at the back(molars) used for ________ andchewing food


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Carnivores-eat the meat of otheranimals

Specially adapted ______ canines

Herbivores- only eat plants

Have no _______ at all

Front teeth adapted for biting and cutting

grass and the molars are designed forchewing _____ matter


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Cows digestive system

Structure of an animals digestive system is adapted to suit whatthe animal eats.

______ is a plant fiber that cannot be digested by humans.Herbivores, such as cows are able to digest cellulose because they

have special ______ living in their ___________stomachsCows chew their food and swallow it. Later on, they bring the foo

back up and chew again. This is known as _____________.After chewed second time, it goes into another part of stomach,

where bacteria break down the cellulose in the process ofchemical digestion


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The digestive systems of some other animals Birds do not have ______ at all. They peck their food into smaller parts before

swallowing it and storing in in their crops. When food leaves the crop, it enters a chamber called a ________. In most birds,

the gizzard holds grit and small stones that the bird has swallowed. These work together with the strong muscular walls of the gizzard to break down the

food. Snakes are able to eat whole live animals that are bigger than their mouths. They do this by unhinging their ______ to allow the food to pass through into the

oesophagus Once the prey is in the oesophagus, strong muscles move it onwards. The snakes have

extremely powerful ________juices, which allow it to digest bones, teeth and fur Earthworms live in soil and eat decaying plant material. They, like birds, store their food in a _______ before it enters a gizzard. The gizzard has strong muscular walls, which help to crush and break down food Digested food is absorbed from the intestine and dirt, stones and undigested food are

passed out through the _______

Chapter 2_International Science (FOOD and DIGESTION

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