What are reactants of light reactions?

What are reactants of light reactions?

The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the sun’s energy are necessary for photosynthesis to occur.

What is the product of light independent reactions in photosynthesis?

The light-independent reactions (Calvin cycle) use stored chemical energy from the light-dependent reactions to “fix” CO2 and create a product that can be converted into glucose. The ultimate goal of the light-independent reactions (or Calvin cycle) is to assemble a molecule of glucose.

What reactants are needed for the light reaction light dependent reaction to start?

The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage molecule ATP and the reduced electron carrier NADPH. In plants, the light reactions take place in the thylakoid membranes of organelles called chloroplasts.

What are the light-dependent reactions products?

The products of the light-dependent reactions, ATP and NADPH, are both required for the endergonic light-independent reactions. The light-dependent reactions involve two photosystems called Photosystem I and Photosystem II.

How are the light-dependent and light-independent reactions related?

In the light-dependent reactions, energy from sunlight is absorbed by chlorophyll and that energy is converted into stored chemical energy. In the light-independent reactions, the chemical energy harvested during the light-dependent reactions drives the assembly of sugar molecules from carbon dioxide.

What is the first set of light-dependent reactions?

The first major set of processes in photosynthesis, in which light energy is initially converted into chemical energy as ATP and NADPH, takes place across the chloroplast thylakoid membranes, between the chloroplast stroma and the thylakoid space.

What is the main function of the light-independent reactions?

Light reactions harness energy from the sun to produce chemical bonds, ATP, and NADPH. These energy-carrying molecules are made in the stroma where carbon fixation takes place. The light-independent reactions of the Calvin cycle can be organized into three basic stages: fixation, reduction, and regeneration.

What comes first ps1 or ps2?

Though the two photosystems in the light-dependent reactions got their name in the series, they were discovered, but the photosystem II (PS II) comes first in the path in the electron flow and then the photosystem I (PSI).

What is common to both photosystems I and II?

What is common to both photosystems I and II? In the photosystem I reaction center, light energy captured by pigment molecules is passed to a special reaction center chlorophyll a called: chlorophyll II.

What is the difference between photosystem I and photosystem II?

Photosystem I is very receptive to light waves at the 700 nm wavelength. In comparison, photosystem II is very receptive to light wavelengths of around 680 nm. Photosystem II produces ATP while photosystem I produces NADPH.

What are the two types of photosystem?

There are two kinds of photosystems: photosystem I (PSI) and photosystem II (PSII) (Fig. 3.3). PSII acts first during the light transformation process in photosynthesis, but it was named PSII because it was discovered second.

What connects the 2 photosystems in the light reactions?

What connects the two photosystems in the light reactions? An electron transport chain connects the two photosystems in the light reactions. ATP and NADPH are both products of the light reactions and are used to power the Calvin cycle.

What happens to the electrons that are lost by photosystem 2?

The two electrons lost from photosystem II are replaced by the splitting of water molecules. Water splitting also releases hydrogen ions into the lumen. This contributes to a hydrogen ion gradient similar to the one created by mitochondrial electron transport.

What is the electron acceptor in photosystem 2?

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. In PSI, the electron gets the energy from another photon. The final electron acceptor is NADP.

Is P680 photosystem 2?

P680, or photosystem II primary donor, (where P stands for “pigment”) refers to either of the two special chlorophyll dimers (also named special pairs), PD1 or PD2. Oxidized P680 (P680+) is the strongest biological oxidizing agent known. It has an estimated redox potential of ~1.3 V.

What is the final electron acceptor of cellular respiration?


What is a primary electron acceptor?

When a photon raises a chlorophyll electron to a higher energy level, that energy, and ultimately an electron, has to go somewhere. That somewhere, ideally for the photosynthesizing organism, is known as the Primary Electron Acceptor. The reducing agent is called pheophytin and is a derivative of chlorophyll itself.

What are the reactants and products of the light independent reactions quizlet?

The products of light-dependent pathways of photosynthesis are Oxygen, ATP, and NADPH. The reactants of light-independent reactions are ATP, NADPH, and Carbon Dioxide. The main purpose of the light independent reaction is to produce glucose.

What are the light dependent reactions products?

Where do light-independent reactions occur?

Photosynthesis occurs in the chloroplasts, the light-dependent reactions are located on the innermost membrane of chloroplasts called thylakoid membrane and light-independent reactions occur in the cytoplasm of the chloroplasts called stroma [17].

Where does the oxygen released during the light-dependent reaction comes from?

The oxygen released during photosynthesis comes from the splitting of water during the light-dependent reaction.

How oxygen is produced during light reaction?

During the light reaction in photosynthesis, oxygen is released as by product by absorbing light energy by chlorophylls. Source of this oxygen is water. Water splits into hydrogen and hydroxyl ions. The hydroxyl ions released oxygen.

What is water split into in light-dependent reactions?

The two photosystems absorb light energy through proteins containing pigments, such as chlorophyll. The light-dependent reactions begin in photosystem II. In PSII, energy from sunlight is used to split water, which releases two electrons, two hydrogen atoms, and one oxygen atom.

What is the purpose of water in the light reaction?

In the process of photosynthesis, water provides the electron that binds the hydrogen atom (of a water molecule) to the carbon (of carbon dioxide) to give sugar (glucose). Water acts as a reducing agent by providing H+ ions that convert NADP to NADPH.

How is carbon dioxide used in the light-independent stage?

In plants, carbon dioxide (CO2) enters the leaves through stomata, where it diffuses over short distances through intercellular spaces until it reaches the mesophyll cells. Once in the mesophyll cells, CO2 diffuses into the stroma of the chloroplast, the site of light-independent reactions of photosynthesis.

What photosynthesis waste product is formed in the light-dependent reactions?

oxygen gas

What two products of light reactions are used up?

What two products of the light reactions are used up in the calvin cycle? NADPH, which is an electron carrier and can be reused, and ATP, or ADP, which is an energy molecule that can be rebuilt in another light reaction.

What two products of the light-dependent reactions are used up in the light independent reaction?

2. The light-dependent reactions convert light energy into chemical energy. The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce ATP and NADPH. These two energy-storing molecules are then used in the light-independent reactions.

What is the net result of Calvin cycle?

Each turn of the Calvin cycle “fixes” one molecule of carbon that can be used to make sugar. It takes three turns of the Calvin cycle to create one molecule of glyceraldehyde-3 phosphate. After six turns of the Calvin cycle, two molecules of glyceraldehyde-3 phosphate can be combined to make a glucose molecule.

Why are the light independent reactions called a cycle?

The light-independent reactions are sometimes called the Calvin cycle because of the cyclical nature of the process. After the energy is transferred, the energy carrier molecules return to the light-dependent reactions to obtain more energized electrons.