Photosynthesis
Define Photosynthesis
A chemical reaction by which plants convert carbon dioxide and water into glucose and oxygen using light energy
Where is chlorophyll found?
In the chloroplasts
Name the tiny holes in the leaf surface used for gas exchange
Stomata
What substance do plants store glucose as?
Starch
What chemical is used to test a leaf for starch?
Iodine
Name the two reactants needed for photosynthesis
Carbon Dioxide and Water
Describe the function of guard cells and stomata
Guard cells open and close stomata to control gas exchange and water loss
What process allows carbon dioxide to enter the leaf?
Diffusion
What happens to the rate of photosynthesis when light intensity increases?
The rate of photosynthesis increases (up to a point)
Why is the leaf boiled in water before testing for starch
To kill the leaf, and break down the cell wall and cell membrane
Name the two products of photosynthesis
Glucose and Oxygen
Describe the function of chloroplasts
To absorb light energy for photosynthesis
Describe how oxygen leaves the leaf
Oxygen diffuses out through the stomata
Where do plants store starch?
Leaves, Organs (fruit & veg)
Why is a leaf heated in ethanol during the starch test?
To remove the chlorophyll and decolourise the leaf
What type of energy is needed for photosynthesis
Light Energy (Sunlight)
Describe one adaptation of a root hair cell
Long hair-like extensions give a large surface area for absorbing water and minerals.
Which tissue transports water up through the plant?
Xylem
Explain why a plant in dim light photosynthesises more slowly
Less light energy is available for photosynthesis.
What colour does hydrogen carbonate indicator turn when carbon dioxide increases?
Yellow
State the balanced chemical equation for photosynthesis
6CO2 + 6H2O → C2H12O6 + 6O2
Explain why palisade cells contain many chloroplasts.
To absorb as much light as possible for photosynthesis
Explain why leaves have a waxy cuticle
What would happen to photosynthesis in complete darkness and why?
Photosynthesis would stop because there is no light energy.
What is the observation lens of a microscope?