1. Photosynthesis
Noadswood Science, 2016

2. Photosynthesis To recall the photosynthesis equation
Tuesday, May 29, 2018
Photosynthesis
To recall the photosynthesis equation

3. Precise Learning Photosynthesis is represented by the equation:
Students should recognise the chemical symbols: CO2, H2O, O2 and C6H12O6
Students should be able to describe photosynthesis as an endothermic reaction in which energy is transferred from the environment to the chloroplasts by light.
The glucose produced in photosynthesis may be:
used for respiration
converted into insoluble starch for storage
used to produce fat or oil for storage
used to produce cellulose, which strengthens the cell wall
used to produce amino acids for protein synthesis.
To produce proteins, plants also use nitrate ions that are absorbed from the soil.

4. Photosynthesis What is photosynthesis?
Photosynthesis is the process that produces glucose, the plants food
Photosynthesis uses energy to change carbon dioxide and water into glucose and oxygen
This glucose is used for a variety of things such as making cell walls and proteins

5. Chloroplasts
Photosynthesis takes place in chloroplasts in green plant cells – these contain the pigment chlorophyll that absorbs light energy

6. Equations
light carbon dioxide + water  glucose + oxygen 6CO2+ 6H2O  C6H12O6 + 6O2

7. Glucose
During photosynthesis plants convert carbon dioxide and water into glucose which is used for a variety of things
Respiration > plants use glucose in respiration to release energy (this energy is used for building new cells / growth / gathering minerals from the soil etc…)
Cellulose > glucose is converted into cellulose for making strong cell walls
Amino acid production > glucose is combined with nitrate ions forming amino acids which join to make up proteins

8. Glucose Storage Glucose molecules Starch molecule
Glucose can also be converted into other substances for storage
Lipids > plants can convert some of the glucose they produce into lipids (stored in seeds)
Starch > glucose can be stored as starch so it is ready for use when photosynthesis doesn’t occur (stored in the roots, seeds and leaves)
Glucose molecules
Starch molecule

9. Starch Experiment

10. Photosynthesis

11. Photosynthesis

12. Practice Questions
By what process do plants break down glucose in order to transfer energy to their cells?
What do plants use cellulose for?
What do plants absorb from the soil to make proteins with?
Why is starch better for storage than glucose?

13. Answers
By what process do plants break down glucose in order to transfer energy to their cells – respiration
What do plants use cellulose for – strengthening cell walls
What do plants absorb from the soil to make proteins with – nitrate ions
Why is starch better for storage than glucose – it is insoluble so doesn’t draw in water (which would cause the cells to swell up)