Food and Digestion ♥

Revision cards for Summer '08 exam

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  • Created by: Georgina.
  • Created on: 12-05-08 09:30

What is in food?

You need food to live. All of the nutrients will help your body work properly. Some foods give you energy and other help you grow. Because different foods do different jobs you have to eat lots of different foods to stay healthy.

Food contains water, which you need to survive. Also food contains nutrients. There are six types of nutrients in food, they are:

fat - butter, cooking oil, cream

carbohydrate - rice, bread, potatoes

protein - meat, fish, eggs

vitamins - fruit, vegetables, brown bread, cereal, brown rice

minerals - meat, milk, salt, seafood

fibre - fruit, vegetables, cereal

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Why is food important?

Fats, proteins, carbohydrates and fibre all have different jobs to do in your body. They are:

fat - and energy store, a vital part of cell membranes

protein- or growth and repair of tissues

carbohydrate - an immediate source of energy

fibre - to keep waste moving through your digestive system fairly quickly

Vitamins and mierals also play an important smaller role inyour diet. They also have different jobs inside your body. They are:

A - keeps skin healthy, good eyesight in the dark

B - keeps nerves healthy

C - keeps gums healthy, keeps skin healthy

D - keeps teeth and bones strong

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Why is food important? Cont.

Why do you need water?

Humans cannot survive without water. A person can live for up to 60 days without eating food, but will die in about 3 days without water. Water has some very important jobs in your body.

Chemical reations - Every chemical reaction in your body happens in water.

Excretion - Your body uses water to dissolve poisonous waste and to get rid of urine.

Transport - Water is used to move othernutreients around your body in the blood.

Cooling - Water cools the body down when you sweat.

Why do you need fibre?

You need fibre to make sure your digestive systtem works properly. Fibre absorbs water which makes it bulky. This gives the muscles in the walls of the digestive system something to push against so that they can keep the food moving through the digestive system fairly quickly.

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A Blalanced Diet

What is a balanced diet?

Your diet is what you eat. A balanced diet provides all the energy and nutrients that you need.

Is a balanced diet the same for everyone?

A balanced diet is the diet bthat you need to stay healthy. One persons balanced diet is different to someone else.

Size - The bigger you are, the more food you need to stay healthy.

Age - Younger people tend to be more active so they need more carbohydrate and fat they need. They are also growing quickly so they need protein. They need calcium and phosphorous to make teeth and bones, and lots of iron to make blood cells. As you grow older you don't need as muc food.

Gender - Men tend to need more enery rich nutrients. Women need more vitamins and minerals.

Activity - If you are always playing sport you will need more carbohdrates and fats. If you are a weight lifter you will need lots of protein. But if you aren't very active and still have lots of carbohydrates and fats you will get fat.

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absorption - what happens when digested food particles pass from the digestive system into the blood stream

acidic - has a pH less than 7, for example stomach acid

alkaline - has a pH greater than 7

amylase enzyme - enzyme responsible fo the breakdown of starch

anus - the end point of the digestive system

balanced diet - range of nutrients needed to stay healthy

blood - fluid responsible for transporting substances from part of the body to another

body temperature - maintained temperature of body, in humans 37°C

carbohydrate - group of energy producing substances, for example starch and sugars

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Glossary cont.

chemical digestion - digestion of food which involves chemicals called enzymes

digestion - the processby which nutrients from food are broken down and absorbed into the body

digestive system - the organs involved in digestion

egested - when undigested waste leaves the body via the anus

energy - ability to do work

enzymes - chemicals found in the digestive system, used to break down large particles into smaller pieces

faeces - undigested waste product that the body via the anus

fat - substance found in food, used as an energy store and part of cell membranes

fibre - food used to keep waste moving through your digestive system

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Glossary cont.

grow - increase in size

mechanical digestion- digestion of food which involves physical action to break food into smaller pieces, for example chewing

minerals - substances required in small amounts by the body

mouth - beggining of the digestive system where food enters the body

nutrients - substances in your food which are needed and used by your body

nutritional label - label found on food packaging which states the amount of each nutrient

protein - food needed for growth and repair of tissues, also used to make enzymes

RDA - suggested ammount of each nutrient which is needed daily to stay healthy

vitamins - substances required in small amounts by the body

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