3.2 esssential intake control and coordination

CHAPTER 3
SCIENCE QUEST 9

Compiled by: M Nortje Year 9 Science/2012 1

Feeling hungry?
Tummy rumbling?
You need to eat to
provide your body
with nutrients.

WWW. nutrition.com.sg
Compiled by: M Nortje Year 9 Science 2

Why do you have to eat?

THE FIVE MAIN GROUPS OF NUTRIENTS.

Nutrients are substances needed
for energy, cell functioning and for
your body's growth and repair.


 Carbohydrates
 Proteins
 Lipids
 Vitamins

 All
CONTAIN CARBON, HYDROGEN AND
OXYGEN

C ,H&O

 EXCEPT MINERALS

 Carbohydrates
& lipids →provide
immediate source of energy and a back-
up supply.

 Proteins can supply some energy, while
their key role → bodybuilding compounds.

 Carbohydrates& lipids nutrients provide
the raw materials required for cell
growth and the repair of damaged and
worn-out tissues.

 Carbohydrates and lipids are also involved in
many other activities in your body:
 Important chemicals such as enzymes and
hormones are made of protein.

 Althoughvitamins have no energy value, they
are needed in small amounts to keep you
healthy and to speed up a variety of
chemical reactions in your body.


 Carbohydrates are found in foods like
pasta, rice, fruits and vegetables.

 Carbohydrates are broken down into
glucose by the digestive system.

 Glucoseis used in aerobic and
anaerobic respiration as a source of
energy.


 Lipids (fats and oils) are very-high-
energy foods that are only needed in
small amounts.

 Lipids are found in deep-fried foods,
dairy foods like butter, cheese and
milk, and in meat.

 Some fast foods and processed foods
are high in fat.


 Proteinsare found in fish, meat,
chicken, eggs, beans, peas, nuts and
dairy foods.

 Proteins are the building blocks of
muscles.

 Peoplewho play sport need to eat
protein-rich foods so that their bodies
can make strong muscles.


 Required in only small amounts, they
are very important to your health.

 They are both needed to control
chemical changes in your body.

 Endocrine system and nervous system
also require a number of these to be
able to effectively function and maintain
a healthy environment for your cells.

A lack of any of the 13 vitamins can cause
disease.
 Diseases caused by a lack of vitamins are
called vitamin deficiency diseases.
 Diseases such as scurvy, rickets and beriberi
have become less common as people have
become more aware of the importance of
vitamins.
 Deficiencies of minerals can also cause a
number of significant problems e.g. In
pregnancy the nutrient need change.

 An example of this is vitamin C which
is needed for the growth and repair of
tendons that hold muscle onto bones.

 Many minerals are found in fresh
fruit and vegetables.


 Match up the nutrients to the descriptions by drawing a line
between the correct nutrient and its description. Finish the
table by providing an example for each.
Example of a food that
Nutrient Match Description contains this nutrient

Inorganic molecules required in
Carbohydrates
small amounts (e.g. iron)
Organic molecules required in
Proteins small amounts for overall good
health (e.g. thiamine)
Provide cells with energy (e.g.
Lipids
sucrose)

High energy nutrients (e.g. fats
Vitamins
and oils)

Essential for growth and repair
Minerals
(e.g. enzymes)

 Vitamins and minerals help keep your body
healthy. Fill in the following table.

Areas of the body where
the vitamins and VITAMIN MINERAL
minerals are needed

Healthy bones and teeth

Helps prevent illness and
aids in wound repair

Helps keep blood cells
functioning

Healthy skin and eyes


 Two third of body is water
 Water makes up about 70% of the
body
 Chemical reactions of cells in body
use and need water
 Blood – 90% water (plasma)
 Blood helps carry nutrients around
your body and wastes away from it
 Water help to cool the body

 Survive 40 days without food BUT
ONLY 3 without water


 Each day you lose water when:
 Breathing out (0.5 litres)
 Sweating (0.5 litres)
 Urinating (1.5 litres)
 During exercise, more water is lost from the
body as sweat.
 Dehydrated - lose too much water.
 A dry throat and mouth and dark-coloured
urine are signs of mild dehydration.
 If you lose more than 20 per cent of your
body's water volume, you could die!

 Only found in the walls of plant
cells – foods like fruit and
vegetables, wholegrain breads and
cereals, nuts and seeds.

 Partially broken down by your
digestive system.
 Although it really does go ‘in one
end and out the other’, it serves a
very useful purpose.
 Essential part of your diet.
 It provides bulk to your food,
allowing it to move properly
through your intestines.


 Without fibre, undigested food travels too
slowly through the large intestine, losing too
much water.

 The result is difficulty in releasing the solid
food waste from the body, a condition called
constipation.

 Lack of fibre in the diet can also lead to
haemorrhoids (varicose veins around the anal
passage, also known as piles), bowel cancer
and several other diseases.

 INQUIRY: INVESTIGATION 3.2 p. 88

 Work in group and use samples on the
bench.
 Complete task and questions.


 UNDERSTANDING AND INQUIRING: p. 89 - 90
 REMEMBER
 THINK AND INVESTIGATE


3.2 esssential intake control and coordination

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (18)

En vedette

En vedette (12)

Similaire à 3.2 esssential intake control and coordination

Similaire à 3.2 esssential intake control and coordination (20)

Plus de nortje

Plus de nortje (19)

Dernier

Dernier (20)

3.2 esssential intake control and coordination

Notes de l'éditeur