The movement of water from a dilute
solution to a more concentrated
solution across a partially permeable
membrane
If cell uses up water in its chemical
reactions, the cytoplasm becomes
more concentrated. More water
moves in by osmosis.
If cytoplasm becomes too dilute
because more water is made in
chemical reactions, water leaves
the cell by osmosis.
Red Blood Cells
If solution outside is more dilute
than the cell contents, water will
move into the cell by osmosis. The
cell will swell and may burst.
If the solution outside is more concentrated than the
contents of the cell then the water will move out of the
cell and may shrivel up
Plants
Water moves into the plant cells through osmosis
Causes the vacuole to swell and press
the cytoplasm up against the plant cell
walls. Making the cell turgid.
It keeps the leaves and stems of the plant rigid and firm
therefore the plants need the surrounding area to have a
higher concentration of water. than the cytoplasm
If the surrounding area is more dilute the water would move out and the vacuole would shrivel
up but not as much as the red blood cell because it has a strong cell wall
Active Transport
The movement of particles from
an area of low concentration to
an area of high concentration
against the concentration
gradient
ENERGY IS REQUIRED FROM RESPIRATION
If a cell
makes a lot
of energy it
can carry out
a lot of active
transport
Root Hair Cells
Mineral Ions
Glucose
Kidneys -
reabsorption
of glucose
Small intestine
(diffusion takes place,
but not all substances
work with the
concentration gradient
Sports Drinks
When you exercise you...
Sweat
Water + Mineral Ions
If your body fluids become concentrated water will leave your cells by osmosis, cells become dehydrated and won't work as well
If they are not replaced
the balance is disturbed
and the cells do not
work as efficiently
Release energy by respiration, using up sugar
Needed for respiration
REPLACE THE
SUGAR USED IN
RESPIRATION AND
WATER + MINERAL
IONS LOST IN
SWEAT
Evidence suggests that for normal
levels of exercise water is at least as
effective as sports drinks
Adaptations
LARGE SURFACE AREA
BEING THIN
Provides a shorter
diffusion path
EFFICIENT BLOOD SUPPLY
Moves the diffusing substances away and
maintains a concentration gradient
BEING
VENTILATED
Makes gaseous exchange
more efficient by
maintaining steep gradients
The Lungs
Made up of alveoli
Large surface area Most effective for diffusion of oxygen and carbon dioxide
Rich blood supply, maintains concentration
gradient in both directions
Layer of cells between the air in the lungs and the blood in
the capillaries is very thin - short diffusion path
Ventiating the lungs
BREATHING IN
Your intercostal muscles
contract pulling your ribcage
up and out
Your diaphragm muscles contract, this
flattens our diaphragm from it's normal
domed shape
Increases the volume of your thorax, and decreases the
pressure- air moves into the lungs
BREATHING OUT
The intercostal muscles relax,
your rib drops down and in again.
Diaphragm relaxes and curves
back up into your thorax
Volume of thorax decreases, increasing the pressure inside your chest and forcing the air out
BREATHING SYSTEM
The lungs are in your thorax protected by your ribcage and
separated from your diaphragm by your abdomen
The Gut
Food is broken down and molecules get turned into simple sugars,
such as glucose, amino acids, fatty acids, and glycerol
Need these products of digestion to provide fuel for respiration and the
building blocks for growth and repair.
Food molecules now small enough to pass freely through
walls of the small intestine into the blood vessels
DIFFUSION
Steep
concentration
gradient
lining of small intestine folded into thousands of
tiny finger like projections known as VILLI (then microvilli)
Increases surface area
Good blood supply - carries digested food away
as soon as it diffuses from one side to the other
network of capillaries
ACTIVE TRANSPORT
Time since last meal gets longer you can
have more dissolved food molecules in your
blood than in your digestive system
Glucose and other dissolved
food molecules then move
from the small intestine to the
blood by active transport
In Plants
Transpiration
Transporting Materials B3.2
The Circulatory System and the Heart
Made up of 3 parts: the pipes (blood
vessels), the pump (the heart) and the
liquid (the blood)
Double Circulation
One carries blood from your heart to your
lungs and back. The other carries blood
around the rest of your body and back again
to the heart
Arteries carry
blood away from
your heart to the
organs of your
body
Blood returns to the heart
through the veins
Heart as a pump
Walls of your heart
are mosly muscle,
muscle supplied with
oxygen by the
coronary arteries
Valves make sure the blood flows in
the right direction through the heart
Blood enters the top
chambers of your heart
THE ATRIA
The blood in the right atrium is from the
VENA CAVA and is DEOXYGENATED
blood from your BODY
The atria contract together and force
blood down into the VENTRICLES.
Valves close to stop the bloos flowing
backwards out of the heart
The ventricles contract and force blood out of the heart
The right ventricle forces deoxygenated blood to the lungs in the pulmonary artery
The left ventricle forces out oxygenated blood to the body through the aorta
The blood in the left atrium is from the
PULMONARY VEIN is OXYGENATED
blood from your LUNGS