Questions and answers

What are two products of photosystem 2?

What are two products of photosystem 2?

Photosystem II obtains replacement electrons from water molecules, resulting in their split into hydrogen ions (H+) and oxygen atoms. The oxygen atoms combine to form molecular oxygen (O2), which is released into the atmosphere.

What does photosystem 2 use and produce?

Photosystem II is the first link in the chain of photosynthesis. It captures photons and uses the energy to extract electrons from water molecules. First, when the electrons are removed, the water molecule is broken into oxygen gas, which bubbles away, and hydrogen ions, which are used to power ATP synthesis.

Does photosystem 2 produce ATP?

Electrons are transferred sequentially between the two photosystems, with photosystem I acting to generate NADPH and photosystem II acting to generate ATP. Electron transport through photosystem II is thus coupled to establishment of a proton gradient, which drives the chemiosmotic synthesis of ATP.

What is the job of photosystem 2?

Photosystem II (PSII) is a multi-component pigment-protein complex that is responsible for water splitting, oxygen evolution, and plastoquinone reduction.

Is oxygen used in photosystem 1?

Light energy (indicated by wavy arrows) absorbed by photosystem II causes the formation of high-energy electrons, which are transferred along a series of acceptor molecules in an electron transport chain to photosystem I. The oxygen atoms combine to form molecular oxygen (O2), which is released into the atmosphere.

What is produced in photosystem 1?

Ultimately, the electrons that are transferred by Photosystem I are used to produce the high energy carrier NADPH. The combined action of the entire photosynthetic electron transport chain also produces a proton-motive force that is used to generate ATP.

What happens if photosystem 2 is inhibited?

Blocking electron transport in PSII systems promotes the formation of highly reactive molecules that initiate a chain of reactions causing lipid and protein membrane destruction that results in membrane leakage allowing cells and cell organelles to dry and rapidly disintegrate.

Is oxygen produced in photosystem 1?

Hint: In photosystem I, the electron comes from the transport chain of the chloroplast electron. When the electron is removed from the water molecule, the photosystem II separates the water and releases the oxygen gas. This reaction is the source of all the oxygen we breathe.

What happens if photosystem 1 is blocked?

A herbicide that disrupts photosystem 1 disturbs the electron transport in the light reaction of photosynthesis. It leads to the deficiency of NADPH because photosystem 1 is the electron donor for the NADPH production. The secondary effect of a herbicide that targets photosystem 1 is it disrupts the membrane.

Which inhibits or stops photolysis of water?

One way to eliminate the generation of O2 from splitting water molecules during photolysis is to use photosystem II inhibitors. Carbonyl cyanide m-chlorophenyl hydrazone (CCCP) has long been recognized as a photosystem II inhibitor of cyanobacteria and green algae [10].

What are the 2 types of photosystem?

There are two types of photosystems in cyanobacteria, algae and higher plants, called photosystem I (PSI, plastocyanin-ferredoxin oxidoreductase) and photosystem II (PSII, water-plastoquinone oxidoreductase), both of which are multisubunit membrane complexes.

How many cofactors are there in photosystem II?

Each photosystem II contains at least 99 cofactors: 35 chlorophyll a, 12 beta-carotene, two pheophytin, two plastoquinone, two heme, one bicarbonate, 20 lipids, the Mn. 4CaO. 5 cluster (including two chloride ions), one non heme Fe 2+. and two putative Ca 2+.

What are the PDB accession codes for photosystem II?

There are several crystal structures of photosystem II. The PDB accession codes for this protein are 3WU2, 3BZ1, 3BZ2 (3BZ1 and 3BZ2 are monomeric structures of the Photosystem II dimer), 2AXT, 1S5L, 1W5C, 1ILX, 1FE1, 1IZL. By convention, gene names are formed by Psb + subunit letter. For example, subunit O is PsbO.

How are electrons transferred to the photosystem II?

Photosystem II. Within the photosystem, enzymes capture photons of light to energize electrons that are then transferred through a variety of coenzymes and cofactors to reduce plastoquinone to plastoquinol. The energized electrons are replaced by oxidizing water to form hydrogen ions and molecular oxygen.

What is the role of photosystem II in photosynthesis?

Photosystem II. By replenishing lost electrons with electrons from the splitting of water, photosystem II provides the electrons for all of photosynthesis to occur. The hydrogen ions (protons) generated by the oxidation of water help to create a proton gradient that is used by ATP synthase to generate ATP.