Questions and answers

Which electron carrier is reduced in the light reactions?

Which electron carrier is reduced in the light reactions?

Nicotinamide adenine dinucleotide phosphate, an energy carrier molecule produced in the light reactions of photosynthesis. NADPH is the reduced form of the electron acceptor NADP+. At the end of the light reactions, the energy from sunlight is transferred to NADP+, producing NADPH.

What is reduced during the light reactions of photosynthesis?

These electrons are used to produce NADPH as well as ATP in a series of reactions called the light reactions because they require light. NADPH and ATP formed by the action of light then reduce carbon dioxide and convert it into 3-phosphoglycerate by a series of reactions called the Calvin cycle or the dark reactions.

What energy carriers are produced during the light reactions of photosynthesis?

In the light-dependent reactions, energy absorbed by sunlight is stored by two types of energy-carrier molecules: ATP and NADPH. The energy that these molecules carry is stored in a bond that holds a single atom to the molecule.

Does cyclic Photophosphorylation occur in low light intensity?

It takes place under the condition of low light intensity and light of wavelength lower than 680 nm and when CO2 fixation is inhibited. Plants are capable of producing energy by utilizing photons from sunlight through photophosphorylation.

What are the raw materials of the light-independent reaction?

Raw materials are Carbon dioxide and water; light reaction happens in plants.

How do plants absorb photons of light energy?

When a plant is exposed to light, photons of appropriate wavelength will strike and be absorbed by the pigment-protein complexes arrayed on the thylakoid membranes. When this happens, the energy of the photon is transferred to the pigment molecule, thus causing the pigment to go into an electronically excited state.

What is co2 fixation?

Carbon fixation or сarbon assimilation is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules.

Why would cyclic Photophosphorylation occur at low light intensity?

Cyclic photophosphorylation occurs when there is no NADP available to act as the final electron acceptor. So the electron from photosystem 1 replaces itself. No photolysis of water take place during Cyclic photophosphorylation so no oxygen is evolved.

What is the ideal condition for cyclic Photophosphorylation?

The low light intensity and anaerobic conditions favour cyclic photophosphorylation while optimum or higher light intensity and aerobic conditions favour non-cyclic photophosphorylation.