Photosynthesis in Higher Plants Test - 5

Each photosystem has all the pigments (except one molecule of chlorophyll a) forming a light harvesting system also called antennae. These pigments help to make photosynthesis more efficient by absorbing different wavelengths of light.

Carotene is present in chloroplast along with chlorophyll pigment. This pigment protect the plants from photo-oxidation during photosynthesis at higher intensity of light.

Excitation of electrons, transfer to another accepter, and finally down-hill to NADP⁺ causing it to be reduced to NADPH⁺ is called the Z scheme.

Certain red and blue wavelengths of light are the most effective in photosynthesis because they have exactly the right amount of energy to energize, or excite, chlorophyll electrons and boost them out of their orbits to a higher energy level.

After absorbing light,electrons are excited and transferred through PS II and PS I and finally to NAD forming NADH.

The Calvin cycle can be described under three stages: carboxylation, reduction and regeneration.Pathway operated in cyclic manner.

During potophosphorylation, electron released during photolysis of water passes through electron transport chain. The electron from exited chlorophyll molecules of Photosystem II are accepted first by quinine.

Electrons become excited and jump into an orbit farther from the atomic nucleus. These electrons are picked up by an electron acceptor which passes them to an electrons transport of cytochrome.

Photosynthesis is the process by which plants, some bacteria and some protistans use the energy from sunlight to produce glucose from carbon dioxide and water. The glucose is used in respiration, or converted into starch and stored.

Light reactions or the ‘Photochemical’ phase include light absorption, water splitting, oxygen release, and the formation of high-energy chemical intermediates, ATP and NADPH. Several complexes are involved in the process.