What is the cyclic photophosphorylation?

Cyclic photophosphorylation can be defined as the synthesis of ATP coupled to electron transport activated by Photosystem I solely, and can therefore proceed in long-wave-length light (03BB 2265 700 nm). This proces is unaffected by the specific inhibitors of Photosystem II, such as CMU, DCMU and orthophenanthroline.

What is photophosphorylation and when does it occur?

In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions.

Where does cyclic photophosphorylation occur?

stroma lamellae membrane
The cyclic photophosphorylation usually occurs in the stroma lamellae membrane of the leaves. It is called a cyclic process because electron providers and electron acceptors are the same .

What is cyclic photophosphorylation Class 11?

Cyclic Photophosphorylation. The photophosphorylation process which results in the movement of the electrons in a cyclic manner for synthesizing ATP molecules is called cyclic photophosphorylation. In this process, plant cells just accomplish the ADP to ATP for immediate energy for the cells.

What is cyclic and noncyclic photophosphorylation?

Cyclic photophosphorylation happens only in the photosystem I but non-cyclic photophosphorylation occurs in both the photosystems I and II. In the cyclic photophosphorylation, only ATP is produced, whereas, in the non-cyclic photophosphorylation both NADPH and ATP are produced.

Why does cyclic electron flow occur?

In cyclic electron flow (CEF), electrons are recycled around photosystem I. As a result, a transthylakoid proton gradient (ΔpH) is generated, leading to the production of ATP without concomitant production of NADPH, thus increasing the ATP/NADPH ratio within the chloroplast.

Where does cyclic photophosphorylation occur in leaves explain the events in sequence?

Cyclic phosphorylation occurs inside the thylakoid membrane of the chloroplast in the leaves. In it basically electrons are recycled, the thylakoid membranes have photo-systems that contain chlorophyll, this chlorophyll helps in the absorption of light energy.

How does cyclic differ from noncyclic electron flow?

In cyclic photophosphorylation, the electrons get expelled by photosystem I and they return to the system. On the other hand, in non-cyclic photophosphorylation, the electrons that are expelled by the photosystems do not return.

Why is photophosphorylation called a cyclic process?

This process is called cyclic because when only PS I is functional, the electron is circulated within the photosystem and photophosphorylation occurs due to the cyclic flow of electrons. The membrane or lamella of the grana have both PS I and PS II, the stroma lamellae membranes lack PS II as well as NADP reductase enzyme.

Where does photophosphorylation occur in the cell membrane?

This type of photophosphorylation usually occurs in the thylakoid membrane. The electron begins in a pigment complex called photosystem I in cyclic electron flow. It then further passes from the primary acceptor to ferredoxin and eventually to cytochrome b6f. Cytochrome b6f is similar to what is found in mitochondria.

What energy is used in photophosphorylation?

In photophosphorylation process, light energy is used to make a high-energy electron donor and a lower-energy electron acceptor. Electrons then move suddenly from donor to acceptor through an electron transport chain. ATP is produced by an enzyme called ATP synthase.

Why is photophosphorylation also called as light reactions of photosynthesis?

ADP molecule gains this phosphate molecule and produces a molecule of ATP. Hence, photophosphorylation is also called as light reactions of photosynthesis.