Photosynthesis essay topics

The chlorophyll bearing plants trap the free energy of sunlight as photons and transform and store it as chemical potential energy by combining CO 2 and water. The end products of photosynthesis are carbohydrates with loss of oxygen. These directly or indirectly serve as the source of energy for all living beings, except chemosynthetic bacteria.

In 1937, R. Hill (British Botanist) was the first to provide evidence that the photochemical reactions of plant cells took place in chloroplasts. Later it was discovered that the oxidized form of the coenzyme NADP + was the normal hydrogen acceptor of the photochemical reaction, producing NADPH.

In the first step the CO 2 combines with a 5-carbon organic compound called ribulose biphosphate (RUBP). This is carbon dioxide acceptor and fixes the CO 2, i. e., incorporates it into the photosynthetic machinery of the plant. The enzyme needed for this is called RUBP carboxylase.

The over all reaction of photosynthesis is — Thus, water is the donor of H 2. The O 2 that is liberated also comes from water and not from CO 2 as has been confirmed by experiments using 18 ‘heavy oxygen – 18 O’. Thus, in this reaction, CO 2 acts as an electron acceptor (A) and H 2 O as an electron donor (D).