National 4/5 BiologySection 4

The Chemistry of PhotosynthesisRaw materials

What do you know?What is the basic word equation for photosynthesis?

A. Glucose + oxygen Carbon dioxide + waterB. Light + Glucose Carbon dioxide + waterC. Oxygen + carbon dioxide Glucose + waterD. Carbon dioxide + water Glucose + oxygen

What do you know?Where does the water come from?

A. LeavesB. FruitC. RootsD. Stem

What do you know?Where does the carbon dioxide come from?How does the carbon dioxide get in to the plant?What happens to the glucose that is produced?What happens to the oxygen that is produced?What two extra things are required for

photosynthesis not shown in the basic equation?

What are we learning today?We are learning to:

- state the word equation for photosynthesis

- understand where the raw materials for photosynthesis come fromSuccess criteria:

- word equation for photosynthesis- what xylem, phloem and stomata are

and what they do- what starch and cellulose are and

where they come from

What are the raw materials for photosynthesis?

The raw materials for photosynthesis are:- Carbon dioxide - Water

How do these things get in to the plant?Carbon dioxide

- through pores in the leafWater

- through the roots- how does it get all the way to the top?- must have vessels for transport

Why is carbon dioxide required for photosynthesis?

Carbon dioxide is required as the source of carbon to make glucose

Carbon dioxide + Water Glucose + OxygenCO2 H2O C6H12O6 O2

What do the pores look like and what are they called?

The pores are called stomataThey allow gases to pass in and out of the leafOnce the gases are in the leaf they can diffuse in to

the cells for use in chemical processes

Look at some stomata under the microscope

Stomata

What can enter and exit through the stomata?

Stomata allow gases in and out as well as allowing water to escape from the leaf.

Guard cells control the opening and closing of stomata

Stomata open during the day to let CO2 and O2 in and out of the leaf and to let water out.

Stomata closed at night to conserve water.

How does the water get from the roots to the leaves?

Plants have a transport system

Xylem vessels are used to transport water and minerals from roots to leaves

They have rings or spirals of lignin to support the plant

Look at some xylem under the microscope

What have we learned today?

Place matWrite down in your

section of the place mat what you learned today

Now as a group decide what you thought the main points were

One person from class shares what their groups main points are

Do the class agree?Structure and function of xylem and phloemWhy stomata are

necessaryThe raw materials for photosynthesis and

how they enter the plant