LEAVES AND PHOTOSYNTHESIS

The Leaf

I can state that leaves are adapted to photosynthesise efficiently

I can describe the basic structure of a leave.

Wednesday 2nd May 2012

Some ways to improve my level

• Read all the question and the paper.

• Give the question some thought

• Use correct key words as often as possible

• Read the graph to the point do not round or approximate.

What do plants need?

1. Sunlight – the plants source of energy2. Chlorophyll – the green stuff which makes

plants look green. 3. Water – travels up from the roots. 4. Carbon dioxide – diffuses in through the holes

in the leaves. Do plants need oxygen?

Question• What is the difference between respiration

and photosynthesis?

Respiration video.

Photosynthesis1. Photosynthesis is the process where ________ make their

own _______. 2. Plants make food which is in the form of g________e.3. Plants need four things to be able to photosynthesise. They

are _______ (from the roots), ______ (through the leaves), __________ (source of energy) and _________ (make plants look green).

4. The word equation for photosynthesis is: ____ _____ + _____ _______ + _______

Leaves work in a similar way to the solar cell. They both need a

lot of light energy to work.

Photosynthesis takes place in the chloroplasts inside the leaf

cells.Can you tell me the word

equation for Photosynthesis?

Chloroplasts contain chlorophyll, a green pigment that takes in energy

from the sunlight.

All green parts of plants are able to photosynthesis because they

contain chlorophyll.

What are products of Photosynthesis?

Electron microscope image

Can you tell me why the leaf is not solid?

Structure of a leaf

PALISADE LAYER

SPONGY LAYER

STOMATA

CUTICLE

VEIN

AIR SPACES

How are palisade cells specialised?

• Lots of chloroplasts, which contain chlorophyll to catch light energy.

• Long and thin, so they pack closely together to collect as much light as possible.

• They are at the top of the leaves, to get as much light as possible.

How does the carbon dioxide get inside the leaf?

Electron microscope image of the underside of a leaf.

Close up of a stoma on the under side of a leaf

What is this for?

Stoma is a small holeIts size is controlled by 2 guard cells What is their function?

closed open

Stoma function is for gas exchange in the leaf

Carbon dioxide

oxygenGuard cell

Provided plant is photosynthesising

Key points• Leaves are usually very ……. so that

sunlight and carbon dioxide can pass through easily

• Broad, flat surface of a leaf ………… the surface area, allowing ……….. sunlight and carbon dioxide to reach cells

• Stomata allow …......... ………. to diffuse into the leaf and oxygen to diffuse out of the leaf

• Veins ……... water and minerals around the plant

Investigating photosynthesis – apparatus

Investigating photosynthesis – experiment

Investigating photosynthesis – results