Question

Label all the components of the diagrams below in detail. (10 pts) Using the two diagrams, explain in detail the process of the Light Reaction in photosynthesis in your own words. If a compound blocks the production of NaDPH, which aspects of photosynthesis would be disrupted. Explain why. OF The diagram below represents

Answer 1

* Diagram

A- Light ( The source of energy for light reaction)

B- water (H2O)

C- Granum

D- Oxygen (O2)

E- Thylakoids

E- ATP

F- NADPH

G- CO2

H- Calvin cycle

I- Sugar

Y- Stroma of the Chloroplast

* LIGHT REACTION ( own words)

In light reaction, light plays an important role. Here a series of chemical reactions take place one after the another initiated by light. Hence this phase is technically termed as photochemical phase. The reactions of the light take place in thylakoid membrane which is present in cholophyll. Thylakoids are termed as the grana of choroplasts.

When sunlight falls on the plant, the chlorophyll present on the leaf absorbs light energy and becomes activated. The absorbed energy excites electrones to the higher energy level. This energy is used to split water molecule into two component ions. It is given by the equation,

H2O } H+ + OH-

The above reaction is termed as photolysis, which means splitting of water by using light. The highly reactive ions of water split in two different directions as OH- and H+ ions. The OH- ions through a series of steps produce water and oxygen. The water produced may be used inside the plant and the O2 is released into the atmosphere. Adenosine tri phosphate (ATP) and Nicotinamide Adenosine Dinucleotide Hydrogen Phosphate ( NADPH) are produced at the end of the light reaction. These are called assimilatory powers. These ATP and NADPH are used in sugar making process.