1. Investigating respiration
Aseel Samaro

3. Plants perform photosynthesis using:
carbon dioxide
Water
energy from sunlight
They produce glucose and give off oxygen.
Without the plant, the mouse would run out of oxygen to breathe. It would die

4. Investigating respiration
Respiration is a process that releases energy.
Every living cell in every living organism needs energy.
Therefore, both plants and animals carry out respiration.
The ways that plants and animals get the glucose needed for respiration vary.

5. Respiration in Plants Just as animals need energy, so do plants.
Plants need energy to:
Grow
Repair tissues
Reproduce
Absorb nutrients.
Respiration uses glucose and oxygen as the reactants.
This is the same in both animals and plants.
Animals use glucose from the food they eat in respiration.
But plants make glucose by a process called photosynthesis. Photosynthesis only happens in plants. It does not occur in animals.

6. Describe what plants need energy for.
Describe a difference between respiration in plants and in animals.
plants make their own glucose; animals take glucose in
Explain what is meant by a ‘reactant’.
It is a starting material in a reaction

7. What is the evidence? You cannot see respiration happening.
However, science experiments can provide evidence that respiration occurs.
When you breathe out onto a cold surface, such as a mirror or window, you see misting or droplets of water.
This suggests that you produce water.
Water is one of the products of respiration.

8. This figure shows an experiment on germinating peas proving that carbon dioxide is given off by living things.
The aspirator draws air through the tubes.

9. Soda lime absorbs carbon dioxide from the air around the seeds.
The seeds produce carbon dioxide and this turns the limewater in flask D cloudy.
Carbon dioxide is also a product of respiration.

10. Describe evidence for the release of water by animals
Describe evidence for the release of water by animals. Suggest how you could test if plants give off water.

11. Did you know…?
Some plants, such as Venus fly traps and pitcher plants, trap insects and digest them.
However, they only use these insects to gain nutrients, not for energy.

12. Respiration and photosynthesis
Photosynthesis and respiration are both vital for plants. We can compare the equations:
Photosynthesis:

13. Respiration:
Interestingly enough, when plants ‘burn’ the glucose produced by photosynthesis it results in a chemical process that is the opposite of photosynthesis.
Plants photosynthesise using sunlight energy.
This is a way of ‘trapping’ the energy.
Respiration releases energy so that the plant can use it.

14. at night – respiration only
List the reactants and the products for both photosynthesis and respiration.
Explain why respiration and photosynthesis are dependent on each other.
because the products of one are the reactants of the other
Suggest whether respiration and/or photosynthesis are carried out by plants:
during the day - both
at night – respiration only

15. Thank you