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Biology A Level > Photosynthesis > Flashcards

Flashcards in Photosynthesis Deck (11):
1

Compensation point

The light intensity level in which the rate of photosynthesis exactly matches the rate of respiration

2

Photosynthetic pigments

Coloured substances that absorb the light energy needed for photosynthesis.

They are light harvesting

3

Example of photosynthetic pigment

Wavelengths of light absorbed in two photosytems

Chlorophyll A

PS1 700nm
PS2 680nm

4

Stroma

It contains enzymes, sugars and organic acids

5

What does reductase do

Accepts protons from the atp synthase pump and joins them with NADP to produce reduced NADP

6

What does ferredoxin do

Accepts e- from PS1 and combines them with NADP in the stroma to make reduced NADP

7

What uses cyclic photophosphorylation

Guard cells

They produce ATP which brings potassium ions into the cells, lowering the water potential so that water follows by osmosis. Swell and opens stomata.

8

How many turns of the calvin cycle is needed for 1 hexose sugar

What can TP be made into

6

Carbohydrates, lipids and amino acids

Carbohydrates= two triose phosphate molecules form a hexose sugar

Lipids= glycerol and fatty acids. Glycerol synthesised from triose phosphate, where as fatty acids from glycerine 3 phosphate

amino acids= glycerine 3 phosphate

9

What colour sunlight does chlorophyll A and B absorb

Red and blue

10

What is the saturation point

Where a factor is no longer a limiting factor

For example, increasing light past this point makes no difference as something else has to be a limiting factor

11

What is a limiting factor

Variable that can slow down the rate of reaction