B4 - Photosynthesis Flashcards
What does photosynthesis mean?
Using light to make food.
What is the word equation for photosynthesis?
Carbon dioxide + water = glucose + oxygen
Why is starch better for storage than glucose?
This is because it is insoluble in water.
What is glucose converted into?
- cellulose to make new cell walls
- proteins for growth and repair
- fats and oils are stored
Why do plants grow quicker in summer months than in winter months?
- they have more light available
- warmer temperatures increase the rate of reaction
Describe Van Helmonts experiment and what his results showed.
Van Helmont grew a tree in a plant pot for 5 year sand measured the mass at the beginning and through time. Since there was little change in soil mass it meant the tree did not gain mass from the soil.
Explain Joseph Priestly’s experiment and what his results showed.
Priestly put a plant in a jar with an enclosed candle. After 27 days he was able to relight the candle, showing the plant produced oxygen.
What are the three limiting factors in photosynthesis?
- carbon dioxide level
- light intensity
- temperature
A plant produces carbon dioxide from respiration 24 hours a day. Explain why it releases more carbon dioxide in the dark.
This is because in the dark it cannot photosynthesise therefore it respires more.
