Page 22 - E-Biology Sec.2 2024-2025 U1_Handy

Blackman

1) Light reactions (Sensitive to light)

They occur in the chloroplast inside the grana as it contains chlorophyll.
They occur in light only and the light is the limiting factor.

O2

1- Light falls on the chlorophyll so, its electrons gain energy and shifted up from

low to higher energy level. “Excited / Activated state”

(kinetic light energy potential chemical in chlorophyll)

2- When the stored energy in the chlorophyll is released, the electrons fall again to

the lower energy levels and chlorophyll returns stable for another influence.

3- The released energy from the excited chlorophyll is used in:

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First Term