ADP takes on energy and a phosphate to produce ATP in photosystem II.
No. Photosystems I and II are where light-dependent reactions occur, while the Calvin Cycle is where light-independent reactions occur. Photosynthesis begins with Photosystem II, then Photosystem I, then the products from there go to the Calvin Cycle. (yes photosystem II comes before photosystem I)
Photosystem 2 is located in the thylakoid membrane of the chloroplasts, while Photosystem 1 is located downstream from Photosystem 2 in the thylakoid membrane. Both photosystems are important for light-dependent reactions during photosynthesis.
In photosynthesis, electrons flow from water molecules to photosystem II, then to photosystem I, and finally to NADP+ ultimately producing NADPH. Along the way, the electrons generate a proton gradient that drives ATP production.
Photosystem's electron travel through the electron transport chain(etc) where ATP is produced and then back to the photosystem. In non-cyclic photophosphorylation, Photosystem II electron then is absorbed by photosystem I, photosystem I electron used to form NADPH and photosystem II gets its electron from photolysis of water. For you unfortunate children using Novanet: They move through an electron transport chain to photosystem 1.
ATP is produced using the energy from photons hitting photosystem II through the process of photosynthesis.
One way to detect the lack of photosystem II in photosynthetic organisms is to measure the rate of oxygen production during photosynthesis. Photosystem II is responsible for splitting water molecules and releasing oxygen as a byproduct, so the absence of photosystem II would result in reduced or no oxygen production. Another method is to analyze the pigment composition of the chloroplasts since photosystem II contains specific pigments like chlorophyll a and beta-carotene. If these pigments are absent or reduced, it can indicate the lack of photosystem II.
Photosystem II is older in terms of evolutionary history compared to Photosystem I. Photosystem II is thought to have evolved before Photosystem I as it evolved to oxidize water in order to provide electrons for the electron transport chain, which Photosystem I then uses to reduce NADP+ to NADPH.
From energy in photons
Photosystem II
Light energy is not exactly trapped. The light energy excites the electron in the reaction centres of photosystem I and photosystem II. The electron excites and transfers to the electron transport chain ( chain of electron carriers), this produces ATP. Then the electron of photosystem II is transferred by photosystem I and the electron of the photosystem I is used with H+ and NADP to form NADPH. Photosystem II gets back an electron from photolysis of water.
Photosystems I and II are both in the thylakoid membranes of the chloroplast.
Photosystem II most likely evolved first because it provides the energy for producing ATP and passes its electrons to photosystem I.