Download Unit 9C and 9D Lesson 1 Photosynthesis

Unit 9C and 9D Lesson 1
Photosynthesis
Objectives: to learn the different parts of the
plant, to learn that light is the energy source
for photosynthesis, and to learn the word
equation for photosynthesis.
Targets: 1-7
Work to Do
• Read pages 82 and 83
• Complete questions 1-8.
• Homework
– Complete Activity Sheet C7S1
– Define the following keywords:
• Stomata, chlorophyll, flower, glucose,
photosynthesis, biomass, chloroplasts
Parts of a Flowering Plant
Leaves are where
photosynthesis take
place. This is where
you find most of the
chlorophyll in the
plant.
The roots take water
and minerals. They
also attach the plant
to the ground and
make sure it doesn’t
blow away.
The flower is the
reproductive part of
the plant. It
produces seeds
which will grow into
adult plants.
The stem gives the
plant support and it
helps to position the
plant in the sun. The
stem also carries
water from the roots
to the leaves.
Photosynthesis
• Photosynthesis is a chemical reaction. It is the way that
plants convert energy from the sun into food.
• Four things are needed for photosynthesis:
–Sunlight
–Water
–Carbon Dioxide
–Chlorophyll: This is the stuff which
makes plants green. It is found in
structures called chloroplasts.
• In photosynthesis plants use sunlight to join molecules of
water and carbon dioxide to form glucose. The plants
then use glucose as food.
• If the plant doesn’t need to use the glucose straight away
it converts it to starch so that it can be stored.
• One of the products of photosynthesis is oxygen which
we use to breath.
Photosynthesis Formula
• The word equation for photosynthesis is:
Sunlight
Water + carbon dioxide
glucose + oxygen
Chlorophyll
Where Does the Carbon Dioxide
and Water Come From?
• The plant gets its carbon dioxide from the air.
• The carbon dioxide enters the plants leaf
through tiny holes called stomata. (One hole is
called a stoma.)
Stoma
• The oxygen which is produced by plants leaves
the leaf through the stomata.
• The water comes from the soil and is absorbed
by the roots.
Stomata Animation
Biomass
• Biomass is a measure of how much mass
a plant has. In other words how much of
the plant there is.
• The glucose which is created along with
minerals absorbed by the roots are turned
into several different chemicals.
• These chemicals help the plant to grow
and add to its biomass.
Factors Which Affect
Photosynthesis
• An increase in the amount of light will
increase the rate of photosynthesis.
• An increase in the amount of carbon
dioxide will increase the rate of
photosynthesis.
• An increase in temperature will increase
the rate of photosynthesis. (This is until it
gets too hot then there will be a sharp
decrease in the rate of photosynthesis.)