Title: Thylakoid
Content:  The thylakoids are the site of the light-dependent reactions of photosynthesis. These include light-driven water oxidation and oxygen evolution, the pumping of protons across the thylakoid membranes coupled with the electron transport chain of the photosystems and cytochrome complex, and ATP synthesis by the ATP synthase utilizing the generated proton gradient.
Title: Light-dependent reactions
Content: 2 + 2 + 3ADP + 3Pi →  + 2 H+ + 2NADPH + 3ATP  In photosynthesis, the light-dependent reactions take place on the thylakoid membranes. The inside of the thylakoid membrane is called the lumen, and outside the thylakoid membrane is the stroma, where the light-independent reactions take place. The thylakoid membrane contains some integral membrane protein complexes that catalyze the light reactions. There are four major protein complexes in the thylakoid membrane: Photosystem II (PSII), cytochrome b6f complex, Photosystem I (PSI), and ATP synthase. These four complexes work together to ultimately produce ATP and NADPH. The photosystems absorb light energy through pigments—primarily chlorophylls, which 
Title: Photosynthesis
Content:  In plants, light-dependent reactions occur in the thylakoid membranes of the chloroplasts where they drive the synthesis of ATP and NADPH. The light-dependent reactions are of two forms: cyclic and non-cyclic. In the non-cyclic reaction, the photons are captured in the light-harvesting antenna complexes of photosystem II by chlorophyll and other accessory pigments (see diagram at right). The absorption of a photon by the antenna complex loosens an electron by a process called photoinduced charge separation. The antenna system is at the core of the chlorophyll molecule of the photosystem II reaction center. That loosened electron is taken up by the primary electron-acceptor molecule, pheophytin. As the 
Title: Light-dependent reactions
Content:  In chemistry, many reactions depend on the absorption of photons to provide the energy needed to overcome the activation energy barrier and hence can be labelled light-dependent. Such reactions range from the silver halide reactions used in photographic film to the creation and destruction of ozone in the upper atmosphere. This article discusses a specific subset of these, the series of light-dependent reactions related to photosynthesis in living organisms.
Title: Light-dependent reactions
Content:  responsible for the green color of leaves. The light-dependent reactions begin in photosystem II. When a chlorophyll a molecule within the reaction center of PSII absorbs a photon, an electron in this molecule attains an excited energy level. Because this state of an electron is relatively unstable, the electron is transferred to an electron acceptor molecule creating a chain of redox reactions, called an electron transport chain. Electrons flow from PSII to cytochrome b6f to PSI. In PSI, the electron receives energy from another photon. The final electron acceptor is NADP+. In oxygenic photosynthesis, the first electron donor is water, creating oxygen as a high-energy waste 
Title: Light-dependent reactions
Content:  reactions. The net-reaction of all light-dependent reactions in oxygenic photosynthesis is:  The two photosystems are protein complexes that absorb photons and are able to use this energy to create a photosynthetic electron transport chain. Photosystem I and II both use special proteins, called light-harvesting complexes, to absorb the photons with very high effectiveness. If a special pigment molecule in a photosynthetic reaction center absorbs a photon, an electron in this pigment attains the excited state and then is transferred to another molecule in the reaction center. This reaction, called photoinduced charge separation, is the start of the electron flow and transforms light energy into chemical forms.
Title: Biology
Content:  more concentrated in the lumen than in the stroma. This is analogous to the proton-motive force generated across the inner mitochondrial membrane in aerobic respiration. During the third stage of photosynthesis, the movement of protons down their concentration gradients from the thylakoid lumen to the stroma through the ATP synthase is coupled to the synthesis of ATP by that same ATP synthase. The NADPH and ATPs generated by the light-dependent reactions in the second and third stages, respectively, provide the energy and electrons to drive the synthesis of glucose by fixing atmospheric carbon dioxide into existing organic carbon compounds, such as ribulose bisphosphate (RuBP) in a sequence of light-independent (or dark) reactions called the Calvin cycle.
Title: Light-dependent reactions
Content:  The first ideas about light being used in photosynthesis were proposed by Colin Flannery in 1779 who recognized it was sunlight falling on plants that was required, although Joseph Priestley had noted the production of oxygen without the association with light in 1772. Cornelis Van Niel proposed in 1931 that photosynthesis is a case of general mechanism where a photon of light is used to photo decompose a hydrogen donor and the hydrogen being used to reduce. Then in 1939, Robin Hill demonstrated that isolated chloroplasts would make oxygen, but not fix, showing the light and dark reactions occurred in different places. Although they are referred to as light and dark reactions, both of them take place only in the presence of light. This led later to the discovery of photosystems I and II.
Title: Light-dependent reactions
Content:  The reaction center is in the thylakoid membrane. It transfers absorbed light energy to a dimer of chlorophyll pigment molecules near the periplasmic (or thylakoid lumen) side of the membrane. This dimer is called a special pair because of its fundamental role in photosynthesis. This special pair is slightly different in PSI and PSII reaction centers. In PSII, it absorbs photons with a wavelength of 680 nm, and is therefore called P680. In PSI, it absorbs photons at 700 nm and is called P700. In bacteria, the special pair is called P760, P840, P870, or P960. "P" here means pigment, and the number following it is the wavelength 
Title: Light-dependent reactions
Content:  PSI accepts electrons from plastocyanin and transfers them either to NADPH (noncyclic electron transport) or back to cytochrome bb6f (cyclic electron transport): plastocyanin → P700 → P700* → FNR → NADPH ↑               ↓                            b6f        ←    phylloquinone PSI, like PSII, is a complex, highly organized transmembrane structure that contains antenna chlorophylls, a reaction center (P700), phylloquinone, and a number of iron-sulfur proteins that serve as intermediate redox carriers. The light-harvesting system of PSI uses multiple copies of the same transmembrane proteins used by PSII. The energy of absorbed light (in the form of delocalized, high-energy electrons) is funneled into the reaction center, where it excites special chlorophyll molecules (P700, with maximum light absorption at 700 nm) to a higher energy level. The process occurs with astonishingly high efficiency. Electrons are removed from excited chlorophyll 

Question: which is the site of the light dependent reactions of photosynthesis?
Answer: thylakoid membranes.
the thylakoid membranes.