Topic 2-Photosynthesis Flashcards
(25 cards)
What is chlorophyll and where is it found
It is a green pigment found in chloroplasts
How does gas exchange occur in a leaf
They pass through the stomata, which is on the underside of the leaf, which is surrounded by a pair of guard cells
How are the roots of a plant adapted to absorb water
They have root hair cells which increase surface area
What does chlorophyll do
It absorbs light energy
Where does carbon dioxide come from
The surrounding air
Where does water come from
It is absorbed by the plants roots from the soil
What are the products of photosynthesis
Oxygen and Glucose
State the word equation for photosynthesis
Light
Carbon dioxide + Water ————> Glucose + Oxygen
Chlorophyll
State and balance the symbol equation for photosynthesis
Light
6CO2 + 6H2O —————> C6H12O6 + 6O2
Chlorophyll
What type of reaction is photosynthesis
It is an endothermic reaction, this means heat energy is absorbed during the reaction
What are the factors that affect the rate of photosynthesis
Light (intensity + wavelength)
Carbon Dioxide concentration
Temperature
At what temp do the plant enzymes begin to denature
Above 40oC
What are the layers of a plant leaf
Cuticle Upper epidermis Palisade layer- chloroplast filles cells Spongy mesophyll layer Lower epidermis- Guard cells and stomata
What are the adaptations a plant leaf has to absorb light
Thin- short distance from top to bottom
Large surface area
Waxy cuticle- transparent and stops water from evaporating
Upper epidermis- transparent
Palisade mesophyll layer- cells filled with chloroplasts and packed tight together
What are the adaptations a plant leaf has for gas exchange
Spongy mesophyll layer- air spaces which allows carbon dioxide in and let oxygen out
Stomata- allows carbon dioxide to enter leaf and allows oxygen to leave leaf
When does photosynthesis occur in plants
Only when light is available
When does respiration occur in plants
It occurs all the times
State the word equation for Respiration
Oxygen + Glucose ———> Carbon dioxide + Water
State and balance the symbol equation for Respiration
6CO2 + 6H2O ———> C6H12O6 + 6O2
When does Photosynthesis occur more than Respiration
In bright daylight- more CO2 will be taken in than O2 can be released
When does Photosynthesis occur less than Respiration
In darkness- more CO2 will be released than O2 can be absorbed
What is the Compensation point
The point at which the rate of photosynthesis and respiration is equal in a plant
When does the Compensation point normally occur
At dawn and dusk
What is Hydrogen-carbonate indicator used to test for
It is used to test fo the concentration of Carbon Dioxide in a solution
More CO2, Normal, Less CO2
Yellow Red Purple
