Photosynthesis

1
Photosynthesis
2
What is Photosynthesis?

• The process of photosynthesis is a chemical
  reaction.
• It is the most important
• chemical reaction on our planet.

3
What is the equation for the chemical reaction of
photosynthesis?
4
Describe Photosynthesis
5
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

6
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

7
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

8
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.

9
Why is this important to us?

• The oxygen released during photosynthesis is
  necessary for all living things.

10
How is photosynthesis related to respiration?
11
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

12

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.

13

• 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.

14

• 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.