1. PLANT NUTRITION
How do plants eat?

2. Some basic plant functions:
Make food using raw material
raw material: carbon dioxide, sunlight, nutrients in soil
Takes in water through roots
The water leaves through the leaves

3. What plants need to eat Water Carbon dioxide Microorganisms help
reactant in photosynthesis
Carbon dioxide
Microorganisms help
they fix essential elements in the soil
Sunlight
provides energy for photosynthesis

4. Photosynthesis “photo” means light
synthesis: putting something together
use light –from the sun– to convert carbon dioxide and water into oxygen and carbohydrates

5. How do the reactants get in the plant?
Stoma (plural: stomata): tiny openings in leaves that lets raw materials in
open during the day
closed at night
more than 90% of water taken in is lost through stomata every day.

6. Chlorophyll: solar cells
chlorophyll pigments in chloroplasts: absorbs light energy
cause for green coloration of plants
Chloroplasts in spinach leaf
General structure of chloroplast

7. What happens next? Water: absorbed through roots, travels to leaves
Carbon dioxide: absorbed through stomata
Light energy: absorbed by chlorophll
Water & carbon dioxide move to chloroplasts where the reaction takes place.

8. What happens to the products of photosynthesis?
Carbohydrates:
broken down inside plant to provide energy to carry out plant functions.
stored in cells for later use
Oxygen: released through stomata into atmosphere

9. Photosynthesis as a process

10. Microorganisms help too
Microorganisms in the soil fix essential nutrients so plants can use them
Without their help, nitrogen would be totally unavailable for us to use
Nitrogen fact: Nitrogen makes up 78% of Earth’s atmosphere

11. Are plants important?
Safe level of oxygen in the atmosphere for humans: 18-25%
Level of oxygen in the atmosphere today: 21%
All thanks to the photosynthesis