5.1.5 Photosynthesis Flashcards
What is the equation for photosynthesis?
6Co2 + 6H20 —> C6H12O6 + 6O2
What is autotrophic nutrition
Photosynthesis turns light energy into chemical energy, which organisms, use to make larger organic molecules from simple inorganic molecules such as water and Co2
What do photosynthetic yutes use to respire?
They use the organic molecules from photosynthesis to release energy
What do non photosynthetic (heterotrophs) yutes use to respir?
They digest complex organic molecules and use these products to get energy
Plants respire all the time but only photosynthesise during the day. What is the compensation point and period?
When the rate of respiration and photosynthesis are balanced and the compensation period is the time it takes to reach this compensation point
What does the waxy cuticle do?
Thin layer above the epidermis that Reduces water loss from leaf.
What is epidermis
Has epidermal cells that have no chloroplasts. They prevent water getting out and unwanted substances and organisms getting in like
What is the palisade mesophyll layer
Where most of the photosynthesis occurs. Palisade cells have a lot of chloroplast to help them perform this photosynthesis. They are also packed close together to maximise light absorption
What does the spongy mesophyll do?
Not as closely packed so they can create airspaces inside the lead to enable gases to move in and out. They don’t have as many chloroplast but photosynthesis can still occur here.
What are stomata?
Holes in the leaves that allow gases to diffuse in and out of the leaves. The opening and closing of this is controlled by guard cells. It is also through these stomata that water leaves leaf in process called transpiration
Where does photosynthesis take place?
It’s a two,stage process that takes place all in the chloroplasts
What does the chloroplast contain that is responsible for photosynthesis
Stroma - fluid containing enzymes which catalyse the reactions of the light independent stage
Grana - stacks of thylakoids. In the thylakoid membranes, the photosynthetic pigments are there which are responsible for the light dependent stage
What’s arranged in a funnel shape?
Light harvesting pigments are arranged in a funnel shape called an antennae complex
What are the antennae complexes arranged as
Photosystems I and II
What happens when a pigment receives the appropriate energy level of light?
It boosts the e- to a higher energy level. So in order to drop the e- back into the stable position, it must pass its excess energy on to another pigment molecule. When this happens and e- in the other pigment is excited and the same happens. Eventually the energy gets passed onto the reaction centre
