What is the physiological difference between cyclic and linear electron flow

The reactions involve two types of electron flow in the thylakoid membrane. While linear electron transport generates both ATP and NADPH, cyclic electron transport around photosystem I (PS I) is exclusively involved in ATP synthesis without the accumulation of NADPH.

What is the difference between cyclic and noncyclic electron flow?

So in non-cyclic photophosphorylation, you make oxygen, from splitting the water molecule, you make ATP using the H+ ions and you make NADPH. In cyclic photophosphorylation, you only use photosystem I. There is no splitting of water – the electrons only come from the light harvesting complex.

What does cyclic electron flow require?

Cyclic electron transfer involves only PSI and cyt bf and was first described by Arnon (1). It involves electron flow to generate an electrochemical proton gradient across the thylakoid membrane without net production of reducing equivalents.

What is cyclic flow?

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.

Why is cyclic electron flow important?

In higher plants, the generation of proton gradient across the thylakoid membrane (ΔpH) through cyclic electron flow (CEF) has mainly two functions: (1) to generate ATP and balance the ATP/NADPH energy budget, and (2) to protect photosystems I and II against photoinhibition.

What is ADP and NADP?

ATP – Adenosine triphosphate. ADP – Adenosine diphosphate. NADP – Nicotinamide adenine dinucleotide phosphate. NADPH – The reduced form of NADP. In the Light Dependent Processes i.e Light Reactions, the light strikes chlorophyll a in such a way as to excite electrons to a higher energy state.

What is cyclic electron flow quizlet?

Cyclic electron flow are the electrons excited from P700 in PSI are passed from Fd to the cytochrome complex and back to P700. … An excited electron of P680 is trapped by the primary electron acceptor.

Is photosynthesis cyclic or linear?

Photosynthesis involves linear and cyclic electron flows; as the cyclic electron flow produces ATP more effectively than the linear electron flow without NADPH, the cell efficiently adjusts ATP and NADPH production using the two different pathways.

What is cyclic and non-cyclic process?

A cyclic process consists of a series of changes which return the system back to its initial state. In non – cyclic process the series of changes involved do not return the system back to its initial state.

Where do the electrons come from in cyclic electron flow?

In cyclic electron flow, the electron begins in a pigment complex called photosystem I, passes from the primary acceptor to ferredoxin and then to plastoquinone, then to cytochrome b6f (a similar complex to that found in mitochondria), and then to plastocyanin before returning to Photosystem-1.

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Does cyclic electron flow produce ATP?

Under certain conditions, the photoexcited electrons take an alternative path called cyclic electron flow, which uses photosystem I (P700) but not photosystem II (P680). This process produces no NADPH and no O2, but it does make ATP. This is called cyclic photophosphorylation.

What happens in noncyclic electron flow?

In a process called non-cyclic photophosphorylation (the “standard” form of the light-dependent reactions), electrons are removed from water and passed through PSII and PSI before ending up in NADPH. This process requires light to be absorbed twice, once in each photosystem, and it makes ATP .

What are the products of linear electron flow?

The products of linear electron flow are ATP and NADPH.

What is the primary function of cyclic electron flow quizlet?

The process of cyclic electron flow allows the cell to generate extra ATP without generating more NADPH, thereby providing enough ATP to carry out the Calvin cycle in the stroma of the chloroplasts.

What are the products of linear electron transport and cyclic electron transport What is the role of cyclic electron transport?

Linear electron transport results in the formation of reductant and ATP, while cyclic electron transport results only in the formation of ATP with no net formation of reductant. The flux of electrons through these pathways is regulated at the level of the cytb6f complex.

What molecule is made during cyclic electron flow?

A second electron transport pathway, called cyclic electron flow, produces ATP without the synthesis of NADPH, thereby supplying additional ATP for other metabolic processes. In cyclic electron flow, light energy harvested at photosystem I is used for ATP synthesis rather than NADPH synthesis (Figure 10.23).

What is the difference between ATP and ADP?

ATP is adenosine triphosphate and contains three terminal phosphate groups, whereas ADP is adenosine diphosphate and contains only two phosphate groups. ADP is produced on hydrolysis of ATP and the energy released in the process is utilised to carry out various cellular processes.

How many ATP and NADPH are made in the light reactions?

The nine molecules of ATP and six molecules of NADPH come from the light reactions.

What is the Calvin cycle in photosynthesis?

The Calvin cycle is a part of photosynthesis, the process plants and other autotrophs use to create nutrients from sunlight and carbon dioxide. The Calvin cycle is a process that plants and algae use to turn carbon dioxide from the air into sugar, the food autotrophs need to grow. …

What is an example of a cyclic process?

In a cyclic process, the system starts and returns to the same thermodynamic state. … A cyclic process is the underlying principle for an engine. If the cycle goes counterclockwise, work is done on the system every cycle. An example of such a system is a refrigerator or air conditioner.

What is the work done in cyclic process?

It is a sequence of processes that leave the system in the same state in which it started. Hence, the work done by the system in a cyclic transformation is equal to the heat absorbed by the system. The net work involved in a cyclic process is the area enclosed in a P-V diagram.

What is non-cyclic process with example?

Non – cyclic Process : A non – cyclic process consists of a series of changes involved do not return the system back to its initial state . Example : Suppose a gas with variables P1,V1,T1 is taken through a series of different sates subjecting to a number of changes including isothermal expansions and compressions .

What is PQ and PC in photosynthesis?

The cytochrome complex, an enzyme composed of two protein complexes, transfers the electrons from the carrier molecule plastoquinone (Pq) to the protein plastocyanin (Pc), thus enabling both the transfer of protons across the thylakoid membrane and the transfer of electrons from PSII to PSI.