Plant Respiration

Photosynthesis

• The process occurring in plants that changes light energy to chemical energy – Energy stored as glucose– Plants need light energy, CO2, and H2O – Takes place in the chloroplast using chlorophyll,

the green pigment in plants

What is Photosynthesis?

Light

+ Carbon Dioxide

+ Water

= Glucose

+ Oxygen

Chemical Equation for Photosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

Carbon Dioxide + Water Glucose + Oxygen

What happens during photosynthesis?

• CO2 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

• Sugar may be: – Used right away by the plant for energy– Stored as starch or– 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.

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

Why is this important to us?

What is Cellular Respiration?

Cellular Respiration

Once the energy that was in sunlight 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

Cellular Respiration

The breakdown of glucose molecules to release energy

Chemical Equation for Cellular Respiration?

C6H12O6 + 602 6CO2 + 6H2OGlucose + Oxygen Carbon Dioxide + Water

Putting it Together!

Putting it Together!

Do Plants Respire?

What happens to the pH of a solution when CO2 is

added?

Try it out!

Bromothymol blue (BTB)

Bromothymol Blue is a pH indicator:• That is yellow in an

acidic solutions • And blue in alkaline

solutions

Do Plants Respire?

The Set Up

1 2 3 4

The Set Up

1 2 3 4

Light Dark

Do Plants Respire?

Baggie Contains

Predictions ResultsLight Dark Light Dark

Elodea ? ?

Nothing ? ?

Make Predictions

• Think about who/what is using and making CO2 in each experiment.

• How does CO2 affect the color of the indicator solution?

Time Lapse

Compare the results with your predictions

Baggie Contains

Predictions ResultsLight Dark Light Dark

Elodea

Nothing