Photosynthesis
What is Photosynthesis?
The process of photosynthesis is a
chemical reaction.
It is the most important
chemical reaction on our planet.
What is the equation for the
chemical reaction of
photosynthesis?
Describe Photosynthesis
Describe Photosynthesis
• The process of changing light energy to
chemical energy
• Energy stored as sugar
• Occurs in plants and some algae
• Plants need light energy, CO2, and H2O
• Takes place in the chloroplasts, using
chlorophyll, the green pigment in plants
What happens during
photosynthesis?
• Plants capture light energy and use that
energy to make glucose
• Sunlight provides the energy needed by
chlorophyll to change molecules of carbon
dioxide and water into glucose
• Oxygen is also released in this reaction
What happens during
photosynthesis?
• Carbon dioxide enters the leaf through holes
called stomata
• CO2 combines with the stored energy in the
chloroplasts through a chemical reaction to
make glucose
• The sugar is moved through tubes in the leaf to
the roots, stems and fruits of the plants
• Some of the sugar is used right away by the
plant for energy; some is stored as starch; and
some is built into plant tissue
Why is this important to us?
We cannot make our own food (glucose,
energy), we must get our food from plants.
Plants are the first step in the food chain.
Without this base life for all heterotrophs
would not be possible.
Why is this important to us?
The oxygen released during photosynthesis
is necessary for all living things.
How is photosynthesis related
to respiration?
16.2 Research
1) What molecule is responsible for
supplying the energy your cells need?
2) Describe the process of photosynthesis
3) What is starch and why do plants need it?
4) Where is chemical energy stored?
5) Are mitochondria in plants or animals,
why and what do they do?
6) Describe the process of cellular
respiration, and fermentation
1) Glucose is the molecule responsible for
supplying the energy our cells need.
2) In photosynthesis the plant takes in carbon
dioxide form the air and water from the soil.
Then as the carbon dioxide and water enter the
chloroplasts the Chlorophyll captures energy
from sunlight and converts the carbon dioxide
and water into new products. Theses are
oxygen and glucose. The plant releases most
of the oxygen into the air and keeps glucose.
3) Glucose that is not immediately used is linked
together to form starch. The plants store starch
and later break it down into glucose or other
sugars when they need energy.
4) Chemical energy is housed in the bonds
between atoms.
5)Mitochondria can be found in both plants and
animals. These organs break the chemical bonds
from glucose into smaller molecules to produce
energy.
6) In cellular respiration changes materials into new
products. It begins with glucose and oxygen. Then glucose
is broken down in the cytoplasm and moved into the
mitochondria along with oxygen. These molecules are
broken down even further and hydrogen is released to
capture energy in a usable form. Finally the products are
energy, carbon dioxide and water.
In fermentation occurs when cells do not have oxygen. The
glucose is broken down in the cytoplasm producing small
amounts of energy. This leads to fermentation where
sugars are broken down into small molecules but they also
produce either alcohol and carbon dioxide or lactic acid.