B1.4 Flashcards
(20 cards)
What are the reactants of photosynthesis?
Carbon dioxide and water
What are the products of photosynthesis?
Glucose and oxygen
How does carbon dioxide enter the plant?
Diffuses from the air into the plant through the stomata
How does water enter the plant?
Enters the roots from the soil through the root hair cells by osmosis.
Why are leaves green?
They contain a pigment called chlorophyll inside their chloroplasts.
What kind of reaction is Photosynthesis?
Endothermic
What is the balanced word equation for photosynthesis?
6CO2 + 6H2O = C6H1206+ 6O2
Where does photosynthesis take place?
Chloroplast
How do you test for starch?
Kill the leaf using boiling water.
place it in a boiling tube of ethanol. (Removes chlorophyll)
Wash the leaf with water (removes chlorophyll)
spread it out on a tile.
Add a few drops of iodine solution.
If starch is there the iodine will turn from yellow-brown to blue-black
What are variegated leaves?
Leaves that only have chlorophyll in some areas of the leaf. Parts without chlorophyll appear as white. Can be used to test if Chlorophyll is needed for photosynthesis.
How can you prove light is needed for photosynthesis?
Take a destarched leaf and cover a part of it with foil, light cannot reach the covered area. Leave the plant in sunlight then test the leaf for the presence of starch.
Which factors affect the rate of photosynthesis? (3 factors)
Light intensity, carbon dioxide, and temperature.
What are factors of photosynthesis called?
Limiting factors
What is the rate of photosynthesis formula?
Rate=1/t where t is time for the measurement to occur
How does light intensity affect the rate of photosynthesis?
Higher the light intensity, the faster the rate of photosynthesis. This continues until photosynthesis reaches its maximum rate.
How does CO2 affect the rate of photosynthesis
Greater the CO2 concentration, the faster the rate of reaction.
How does temperature affect the rate of photosynthesis?
Photosynthesis is a series of enzyme-controlled reactions. Therefore, the higher the temperature the faster the reactions occur. However, if the temperature is too high the enzymes will denature will denature and the reactions will stop.
What is the inverse square law formula?
Relative light intensity = 1/distance from light source squared
A scientist investigated the time taken for ELODEA ( pondweed) to produce 1cm cubed of oxygen gas. The scientists found that for a light intensity of 2500 lux, it took 4 minutes to collect the gas. Calculate the rate of photosynthesis.
0.25 min power of -1
What is the relative light intensity of a light 0.5 metres away from a plant?
4
