Photosynthesis
is the process
that plants use
to get energy
from the sun.
Plants photosynthesise
because they don't eat other
organisms to get energy
(sugar), so they make their
own to survive. They do this
by using the energy provided
by sunlight to form molecules,
that they can turn into sugar.
Plants are important because we can't survive
withouth them as they give out oxygen for
humans and animals to live. Plants are also at
the bottom of every food chain. So if they go,
then everything else will gradually die.
A man made technology
that mimics photosynthesis
is Solar Pannels.
Equation- Carbon Dioxide + Water
-> (Sunlight react together to form....)
Oxygen + Glucose
Plants photosynthesise mostly in the
leaves because they have cell organelles
called chloroplasts. The chloroplasts
contain a green pigment called
chlorophyll (green coloured substance)
that traps the energy from sunlight.
What makes a leaf good at photosynthesis is
they grow where they are exposed to light.
They have lots of chloroplasts (green). It's thin
to allow light through. Anda large surface area.
Diffusion
Is the making the gases
carbon dioxide and oxygen
move in and out of the leaf.
The gases move in and
out of the cells through a
process called diffusion.
Diffucsion happens all by
itself when particles
move from somewhere
with a high concentration
to somewhere with a low
concentration.
Steps on how diffusion works: 1) There
is more carbon dioxide outside the leaf
than there is on the inside of the leaf. 2)
The carbon dioxide the diffuses through
the stoma into the cells in the leaf. 3)
Once in the cells, photosynthesis
happens and the carbon dioxide
changes into oxygen in the palisade
cells. 4) Then as there is a higher
concentration of oxygen inside the leaf
rather than outside, the oxygen then
diffuses back outside through the stoma
and out into the air that we breathe,
Transpiration
Is hot the water moves from the roots to the
leaf. The water moves up the xylem vessels
because of a type of suction. During the day
the water evaporates out of the leaves
through the stomat. This loss of eater
causes more water to be sucked up the
xylem vessel through the roots. This keeps
happening all day until the stoma closes.
Plant Root Cells
Root cells are
responsible for
absorbing all of
the water the
plant needs.
Root hair cells have a hair like
structure to increase their surface
area. This allows them to absorbs
water quickly. They absorb water
through osmotis (same as diffusion)
Xylem are made of lots of
cells which form a hollow tube.
It's job is to transport the water
from the roots to the leaves
like veins in an animal
Leaf Structure
1) Upper Epidermis- Is a layer of
flattened cells that act like a skin for the
leaf. They contain no chloroplasts and
cannot photosynthesise. Stops
unwanted substances from getting in
and out of the leaf
2) Waxy Cuticle- A layer that sits on top of the upper epidermis. It
acts like a sunscreen, preventing the leaf cells from loosing water.