Practise IB Biology HL 8.3.1 by analysing pigment evidence, chloroplast function and conversion of light energy into chemical energy.
In ecosystems, energy is used to convert inorganic compounds into organic matter. Energy enters ecosystems through producers.
Explain the processes by which light energy is converted into chemical energy.
a. plants/producers/autotrophs convert light to chemical energy by photosynthesis
b. chlorophyll/photosynthetic pigments absorb light
c. electrons are excited/raised to higher energy level
d. excited electrons pass along chain of electron carriers
e. energy from electrons used to pump protons across thylakoid membrane/into thylakoid space
f. chemiosmosis/proton gradient used to make ATP
g. ATP synthase generates ATP
h. pigments arranged in photosystems
i. electrons from Photosystem II flow via the electron chain to Photosystem I
j. electrons from Photosystem I are used to reduce NADP
k. ATP and reduced NADP used in the light independent reactions/Calvin cycle
I. carbohydrate/glucose/carbon compounds produced containing energy
Marking guidance:
Award marking points for any point made on a clearly annotated diagram.
8 max