3 Plants and Photosynthesis Flashcards
Photosynthesis equation (word, symbol and balanced)
carbon dioxide + water → glucose + oxygen
CO2 + H2O → C6H12O6 + O2
6CO2 + 6H2O → C6H12O6 + 6O2
Light energy is absorbed by a _____ substance called ____________, which is found in the ____________ of some plants cells and algae.
1) green
2) chlorophyll
3) chloroplasts
Where does carbon dioxide for photosynthesis come from?
The air.
Where does water for photosynthesis come from?
The soil.
1) What is glucose?
2) What is oxygen in photosynthesis?
1) Glucose is a sugar.
2) A by-product.
What do plants use glucose (in photosynthesis) for? (5)
- Respiration (for energy)
- Converting into insoluble starch for storage
- For producing cellulose which strengthens cell walls
- To produce amino acids for protein synthesis
- To produce proteins for plant growth and repair
Plant tissues are gathered together to form ______. The ____ is a plant organ.
1) organs
2) leaf
Stomata
Allows diffusion of gases in and out of the leaf and can be opened and closed by guard cells.
Why is there lots of air space in leaves?
So gases can diffuse.
Why are there many chloroplasts close to the top of the leaf?
To trap as much sunlight as possible.
Epidermis
Covers the outer surface of the plant for protection.
Palisade mesophyll
The main site of photosynthesis in the leaf.
Spongy mesophyll
Air spaces between cells allow gases to diffuse through the leaf.
Xylem vessels (3)
- Transports water and minerals through the plant from roots to leaves
- Supports the plant
- Composed of hollow tubes strengthened by lignin adapted for water transport in the transpiration stream
Phloem vessels (2)
- Transports dissolved food materials through the plant.
* Translocation
State factors affecting photosynthesis. (4)
- Temperature
- Carbon dioxide concentration
- Light intensity
- Chlorophyll concentration
Limiting factors (2)
- “The rate of any given process will be determined by the factor that is in the shortest supply.”
- It is the factor that stops the reaction from going any faster
Meristem tissue
Found mainly at tips of roots and shoots where it can produce new cells for growth.
The rate of photosynthesis may be limited by what? (3)
- Shortage of light
- Low temperature
- Shortage of carbon dioxide
Transpiration (3)
- The movement of water up through a plant (by evaporation) and its loss from the leaves
- Xylem
- Up only
Translocation (3)
- The movement of sugars/dissolved food materials through a plant
- Phloem
- Both ways
Photosynthesis is an ___________ reaction where energy is transferred from the environment to the ____________ by _____.
1) endothermic
2) chloroplasts
3) light
How is a root hair cell adapted to its function? (2)
- Long projection increases surface area to absorb water and minerals
- Lots of mitochondria for active transport of minerals
How is the phloem adapted to its function? (2)
- End walls of cells allow sugars through but also support the tubes (sieve plate)
- Companion cells provide energy
How are xylem cells adapted to their function? (2)
- Cell wall is strengthened and supported by lignin (wood)
* Cells are arranged end to end but end walls break down to form continuous, hollow tubes
