Photosynthesis &

Respiration

1. What is Photosynthesis?

The process plants perform to make their own food

The food they make is a sugar called Glucose (C6H12O6)

2. Where does Photosynthesis take place?• On plant leaves in a place called

chloroplasts

Elodea Plant

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Elodea Plant cells

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Inside of a chloroplast

3. What do plants need for photosynthesis?

1. Carbon Dioxide CO2

2. Water H2O

3. Sunlight (light energy)

4. What do plants make from photosynthesis?

• 1. Glucose (sugar, a.k.a. plant food)C6H12O6

• 2. Oxygen O2

5. What is the equation for the chemical reaction of

photosynthesis?

Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

6CO2 + 6H2O → C6H12O6 + 6O2

6. Describe Photosynthesis• The process of changing light energy

from the sun to chemical energy (food: glucose)

• Takes place in the chloroplasts, using chlorophyll, the green pigment in plants

7. What happens during photosynthesis?

• Chlorophyll absorbs sunlight and uses the energy from light to change molecules of carbon dioxide and water into glucose

• Oxygen is also released

8. Where does CO2 come from?

• Carbon dioxide enters the leaf through a hole on the bottom of the leaf called stomata

Real stomate from a microscope

9. Stomata▪ Stomate ( “sto-ma-tay” plural of

stomata) have guard cells that keep them open or closed

▪ When light is available stomata are open, and at night the stomate are closed.

10. What is Glucose used for?

• Glucose is moved through tubes in the leaf to the roots, stems and fruits of the plants

• Some of the glucose is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue.

11. 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.

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

Cellular Respiration

1.What is Cellular Respiration?

• Once the light energy that was in the sun is changed into chemical energy by photosynthesis an organism has to transform the chemical energy into a form that can be used by the organism.

• This process is cellular respiration

2.Describe Cellular Respiration

• The breakdown of glucose molecules to release energy

• Respiration takes place in all living things (plants & animals)

3.Chemical equation for cellular respiration

C6H12O6 + 6O2

Glucose + Oxygen → Carbon Dioxide + Water + Energy

6CO2 + 6H20 + Energy (ATP)

Hmmm….. look familiar?????

4. Cellular Respiration & Photosynthesis

•Cellular Respiration is the opposite process of Photosynthesis

PhotosynthesisReactants ProductsCarbon Dioxide Glucose

Water Oxygen

Sunlight

Cellular RespirationReactants Products

Glucose Carbon Dioxide

Oxygen Water

Energy (ATP)

5. What is ATP?ATP stands for Adenosine Tri-phosphate• A molecule that provides energy for cellular process in all known organisms.

• Cellular process examples : Cell growth, DNA repair, inflammation, immunity, and fat metabolism (i.e.: burning fat)

Check for Learning1. What is cellular respiration?

Answer: The breakdown of food to release energy

2. Who performs cellular respiration?Answer: Plants and Animals

3. How does Cellular respiration relate to photosynthesis?Answer: It is the reverse process of

photosynthesis