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Where do electrons get their energy from in photosystem 1?

Where do electrons get their energy from in photosystem 1?

Photosystem I receives electrons from plastocyanin or cytochrome c6 on the lumenal side of the thylakoid membrane and uses light energy to transfer them across the membrane to ferredoxin on the stromal side. It can also function in a cyclic electron transport pathway.

Where do photosystem 1 replacement electrons come from?

Photosystem I obtains replacement electrons from the electron transport chain. ATP provides the energy and NADPH provides the hydrogen atoms needed to drive the subsequent photosynthetic dark reaction, or Calvin cycle.

Where do electrons get their energy from in photosynthesis?

While at photosystem II and I, the electrons gather energy from sunlight. How do they do that? Chlorophyll, which is present in the photosystems, soaks up light energy. The energized electrons are then used to make NADPH.

What does photosystem 1 do in photosynthesis?

Photosystem I is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. Ultimately, the electrons that are transferred by Photosystem I are used to produce the high energy carrier NADPH.

Where do electrons get their energy in the light reactions answers?

Answer: The energy of light captured by pigment molecules, called chlorophylls, in chloroplasts is used to generate high-energy electrons with great reducing potential. These electrons are used to produce NADPH as well as ATP in a series of reactions called the light reactions because they require light.

What happens to the electrons after they leave photosystem 1?

After electrons get excited by light a second time (at photosystem I), where do they go? They travel down a second electron transport chain and are donated to ADP, which is then converted to ATP.

What’s the difference between photosystem 1 and 2?

Photosystem I (PS I) and photosystem II (PS II) are two multi-subunit membrane-protein complexes involved in oxygenic photosynthesis. The main difference between photosystem 1 and 2 is that PS I absorbs longer wavelengths of light (>680 nm) whereas PS II absorbs shorter wavelengths of light (<680 nm).

How does each photosystem replace its lost electrons?

Source of electrons. Once an electron is lost, each photosystem is replenished by electrons from a different source. The PSII reaction center gets electrons from water, while the PSI reaction center is replenished by electrons that flow down an electron transport chain from PSII.

What is the process of photorespiration?

Photorespiration is the process of light-dependent uptake of molecular oxygen (O2) concomitant with release of carbon dioxide (CO2) from organic compounds. The gas exchange resembles respiration and is the reverse of photosynthesis where CO2 is fixed and O2 released.

What is the end product of photosystem I?

ATP is the product of photosystem I.

Where do electrons get their energy in light?

The electron can gain the energy it needs by absorbing light. If the electron jumps from the second energy level down to the first energy level, it must give off some energy by emitting light. The atom absorbs or emits light in discrete packets called photons, and each photon has a definite energy.

Which product is the result of light reactions in photosynthesis?

The Light Reactions The energy is then temporarily transferred to two molecules, ATP and NADPH, which are used in the second stage of photosynthesis. ATP and NADPH are generated by two electron transport chains. During the light reactions, water is used and oxygen is produced.