Download Ourselves Powerpoint

S2 Biology
Madras College
• It is important
to maintain a
healthy balance
of :
• Carbohydrates.
• Proteins
• Fats
• Vitamins and
Minerals
• Fibre
• Water
• Carbohydrates are found in these foods above
• We need carbohydrates for energy
• Proteins are
found in
foods such
as :
• Red meat
• Fish
• Eggs
• Cheese
We need proteins for growth and repair
• Fats are high in any
fried or ‘fast’ food
• We need some fats for:
• Proper function of the
heart
• Maintenance of the
blood system
• Brain development and
function
Excess fat is stored under
our skin or around our
organs
• Vitamins and Minerals
are substances which
the body needs in
very small quantities
to work properly.
Vitamin/Mineral
Function
Vitamin A
Eye function
Vitamin B group
Energy from food
(respiration)
Vitamin C
Maintain healthy
skin and gums
Iron
Production of Red
Blood Cells
Calcium
Healthy bones and
teeth (with Vit. D)
Iodine
Maintain normal cell
function
• ‘Junk Food’ contains
many ingredients
which are generally
bad for you. These
are generally known
as…
• Junk food is alright
to have ‘ once in a
while’, but should
not be eaten
regularly.
Enamel
Crown
Dentine
Gum
Pulp Cavity
Root
Cement
Bone
Incisors
• An adult has
32 teeth in
total.
Canines
Wisdom
teeth
Molars
Molars
Pre-molars
• Bacteria on teeth use
sugar from our food. The
Bacteria multiply to form
plaque.
• The Bacteria make acid.
• The acid slowly burns
through the enamel to
create a cavity.
• The bacteria continue to
make acid using food
stuck in the cavity.
Eventually, the cavity
extends to the pulp cavity
and causes toothache!
• It is important to
brush your teeth
regularly!
• Use a good
toothbrush.
• You may wish to use
mouthwash too.
Regular brushing is important for all members of the family!
Mouth
Gullet
Liver
Stomach
Gall
Bladder
Pancreas
Large
Intestine
Small
Intestine
Appendix
Anus
Rectum
• Teeth begin
mechanical
breakdown of food.
• Saliva contains
Amylase
(Carbohydrase)
enzyme to begin
digestion of
Carbohydrates.
• Passes food from
the Mouth to the
Stomach.
• Food is moved
along the gut by a
process called
PERISTALSIS.
• Fibre in the diet
helps the gut move
food along easily.
Muscles in
gullet wall
contract
behind bolus
Bolus
of food
Gullet
Bolus
squeezed
along gut.
• The Stomach churns
our food.
• It makes Protease
enzyme for Protein
digestion.
• It makes Hydrochloric
Acid to kill germs.
Liver
• The Liver makes Bile.
• Bile is stored in the
Gall Bladder.
• Bile breaks down fat
into small droplets.
• This is
EMULSIFICATION.
Gall
Bladder
Bile
Fat
Lipase
enzyme can
now digest
fat easier
Liver
Stomach
Gall
Bladder &
Bile Duct
Small
Intestine
• The Pancreas
makes enzymes for
the digestion of
Carbohydrates,
Proteins and Fats.
• It also helps control
blood/sugar levels.
• Digestion is completed in the Small intestine.
• Small and soluble food particles pass into the blood by absorption.
• The Small intestine has a very large surface area due to Villi.
Blood
capillary
Villus
Small
Intestine
Large food molecules
broken down by
enzymes
Small soluble
food molecules
pass into the
blood.
• Mostly undigested
food and Fibre
passes into the
Large Intestine.
• Water and
Minerals are
absorbed into the
blood here.
• This is the breakdown of large insoluble
molecules into small soluble molecules.
• Digestion allows food to be absorbed by
the blood.
Large Insoluble
Food Molecule
Small Soluble
Food Molecules
If the name ends in –ase,
it’s an enzyme
• Starch is broken down into Sugar (Glucose).
• Amylase is a Carbohydrase enzyme.
Amylase
Starch
Amylase breaks
bonds between
Sugar molecules
Simple Glucose
can now be
absorbed into
the bloodstream
• Proteins are broken down into Amino Acids.
• Pepsin from the Stomach is a Protease enzyme.
Pepsin
Amino Acids are absorbed into the blood
Other Protease enzymes break
down short protein chains into
Amino Acids.
Pepsin breaks
down the long
proteins into
shorter proteins
• Lipase digests Fat.
• Fat is broken down into Glycerol and Fatty Acids.
Lipase enzyme
Glycerol
Fatty Acids
A Fat Molecule
Fatty Acids and
Glycerol absorbed
separately into
bloodstream
• This is the process which your cells use to
make energy.
Larynx
(voice box)
Trachea
(windpipe)
Bronchi
Rib
Bronchioles
Rib muscle
Alveoli or
air sacs are
found at the
ends of the
Bronchioles
Diaphragm muscle
Film of
moisture
Deoxygenated
blood from
heart
Capillary
Oxygenated
blood back to
heart
Diaphragm contracts and moves
downwards.
Rib muscles contract and ribcage moves
upwards and outwards.
Volume in chest increases.
Pressure in chest decreases.
Air is Inhaled.
Diaphragm relaxes and moves upwards.
Rib muscles relax and ribcage moves
downwards and inwards.
Volume in chest decreases.
Pressure in chest increases.
Air is Exhaled.
•
•
Inhaled air is 78% Nitrogen, 20% Oxygen, 1% Carbon Dioxide and 1%
Rare gases.
Exhaled air contains less Oxygen (16%) and more Carbon Dioxide (5%).
Rare Gases
Carbon Dioxide
Oxygen
(20%)
Oxygen
(16%)
Nitrogen
(78%)
Nitrogen
(78%)
In Exhaled air, the
candle goes out
sooner because
there is less Oxygen
in it.
0 seconds
2
4
6
8
10
seconds
Normal Air
Exhaled Air
Exhaled Air
Carbon Dioxide
gas turns
Limewater
cloudy
Limewater
Water turns
blue Cobalt
chloride
paper pink
Cobalt Chloride paper
Cilia
The cilia beat and
move mucus
containing dirt
and germs up to
the back of the
throat
Mucus
Trapped dirt and
germs are moved
towards the
mouth