Monday, August 20, 2012

STPM Biology - chapter 6: Revision essay question 4

4. Define the process of photosynthesis in Bacteria.

Answer


Light reaction occurs in photosynthetic membrane of bacteria.
                    -In present of light, bacteriochorophyll absorbs light energy.
                    -Energy absorbed is then channelled to reaction centre.
                    -Reaction centre becomes photoactivated and photosystem I becomes photoactivated.
                    -Electron of reaction centre becomes excited and escape.
                     Escaped electrons are then transferred through a series of electron carriers and finally
                     back to reaction centre.
                    -As electron carriers transfer electron down the energy level, energy released. Released  
                     energy is used for photophosphorylation of ADP to ATP.
                    -In purple bacteria, hydrogen sulphide is splitted into electrons, sulphur and hydrogen
                      ion. Reverse electron flow to oxidised NADP produces NADPH.
                    -Dark reaction is similar to plants except the process occurs in the cytoplasm of
                      bacteria.

No comments:

Post a Comment