B1.4 Flashcards
What do plants have to take in to make food
CO2 and water
Photosynthesis equation
6CO2 + 6H2O ——— C6H12O6 + 6O2
Where does photosynthesis occur in a cell?
Chlorophyll
How to test for starch
Take a leaf, put it in a beaker and then boil it to kill it. Using forceps put lead into boiling ethanol. Ethanol should be put under a water because it’s flammable. Wash leaf with water to remove excess ethanol. Spread it onto white tile. Add iodine to it. If it goes from yellow- brown to blue- black then starch is present
How to prove chlorophyll is needed for photosynthesis
Get a destarched Veragated plant and put under sun for several hours then rest for starch
How can you prove for light in photosynthesis?
Get a destarched plant and cover one side of the leafy with a black card. Leave plant under the sun for serval hours. Take black ard out and test for starch
Test for co2 in plant
Get a destarched plant and put in a polyethene bag. Put soda lime in bag. Chemical absorbs co2 and water vapour. Put bag under light for several hours and test for starch
How to prove for oxygen in photosynthesis
Upturned Test Tube on an aquatic plant. Put it near light for max photosynthesis. Get a glowing splint, put it near the near the tube of gas and if there is O2 present, it will relight.
How does light intensity affect the rate of photosynthesis?
The higher the light intensity, the faster the rate of photosynthesis. Continues till it reaches the maximum rate. In very low light levels or if there is no light then photosynthesis stops.
How does Carbon dioxide affect the rate of photosynthesis
The greater the co2 concentration, the faster the rate of reaction. Atmosphere has only 0.04% of CO2. Limiting factor.
Farmers artificially increase co2 levels in greenhouses. This increases the rate of photosynthesis.
How does temperature affect the rate of photosynthesis?
Photosynthesis is a series of enzyme controlled reactions. The higher the temp, the fast the rate if reactions. However if the temperature is too high, the enzymes will denature and reactions will stop.
How to investigate the rate of photosynthesis
Use elodea pondweed. The volume of oxygen given off per minute is a measure of the rate of photosynthesis.
How can you alter light intensity to see the rate of photosynthesis?
Place the light source at different distances of the elodea
How can you alter co2 concentration to see the rate of photosynthesis?
Add different masses of potassium hydrogen carbonate powder to the water. Potassium hydrogen carbonate releases co2 to the atmosphere .
How can you alter temperarue to see the rate of photosynthesis?
Place the apparatus is water baths at different temperatures
