Section 4
The Chemistry of Photosynthesis
Raw materials
What do you know?
 What is the basic word equation for photosynthesis?
A. Glucose + oxygen
Carbon dioxide + water
B. Light + Glucose
Carbon dioxide + water
C. Oxygen + carbon dioxide
Glucose + water
D. Carbon dioxide + water
Glucose + oxygen
What do you know?
 Where does the water come from?
A.
B.
C.
D.
Leaves
Fruit
Roots
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 from
 Success 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
 Water
-
through pores in the leaf
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
CO2
H2O
Glucose + Oxygen
C6H12O6 O2
What do the pores look like and what are
they called?
 The pores are called stomata
 They allow gases to pass in and out of the leaf
 Once 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 mat
 Write 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
phloem
Why stomata are
necessary
The raw materials for
photosynthesis and
how they enter the
plant