Terms in this set (7)

Explanation: Water is absolute requirement for photosynthesis to occur. During Light reactions of Photosynthesis, the chlorophyll will be activated by light. Water molecule is split to release H+ ions and also oxygen.

Here are the basic steps:

• Light absorption in PSII. When light is absorbed by one of the many pigments in photosystem II, energy is passed inward from pigment to pigment until it reaches the reaction center.
• ATP synthesis.
• Light absorption in PSI.
• NADPH formation.

• (1st Time) Energy is absorbed from the sun.
• Water is broken down.
• Hydrogen ions are transported across the thylakoid membrane.
• (2nd Time) Energy is absorbed from the sun.
• NADPH is produced from NADP+.
• Hydrogen ions diffuse through the protein channel.
• ADP becomes ATP.

The light-independent reactions of the Calvin cycle can be organized into three basic stages: fixation, reduction, and regeneration.

4 Cards in this Set

What two things are needed for the light-dependent reactions to take place? -Water and light are needed for light-dependent reactions.

In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water. The light-dependent reactions release oxygen as a byproduct as water is broken apart.

The overall function of light-dependent reactions, the first stage of photosynthesis, is to convert solar energy into chemical energy in the form of NADPH and ATP, which are used in light-independent reactions and fuel the assembly of sugar molecules.

Although photosynthesis is most commonly associated with plants, microbial photosynthesis is also a significant supplier of chemical energy, fueling many diverse ecosystems. 1: The light-dependent reactions of photosynthesis (left) convert light energy into chemical energy, forming ATP and NADPH.

The primary function of the light reactions of photosynthesis is to: produce energy-rich ATP and NADPH.

Photosynthesis converts radiant energy into chemical energy.

In higher plants, the generation of proton gradient across the thylakoid membrane (ΔpH) through cyclic electron flow (CEF) has mainly two functions: (1) to generate ATP and balance the ATP/NADPH energy budget, and (2) to protect photosystems I and II against photoinhibition.

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.

Calvin-Benson cycle

In the light-independent reactions or Calvin cycle, the energized electrons from the light-dependent reactions provide the energy to form carbohydrates from carbon dioxide molecules. In addition, several enzymes of the light-independent reactions are activated by light.

Light and dark reactions in photosynthesis Light-independent reactions (dark reactions). Light reactions need light to produce organic energy molecules (ATP and NADPH). They are initiated by colored pigments, mainly green colored chlorophylls. Dark reactions make use of these organic energy molecules (ATP and NADPH).

The leaf disks intake carbon dioxide from a baking soda solution and sink to the bottom of a cup of water. When exposed to light, the disks use carbon dioxide and water to produce oxygen and glucose. Oxygen released from the leaves forms tiny bubbles that cause the leaves to float.

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.

CO2, water, light, and chlorophyll are the raw materials for photosynthesis. But, in case of light dependent reaction or light reaction of photosynthesis, it is most influenced by presence or absence of light.

Oxygen and glucose are both reactants in the process of cellular respiration. The main product of cellular respiration is ATP; waste products include carbon dioxide and water.

What is a dark reaction? In the dark reaction, plants use carbon dioxide with ATP and NADPH from the light reactions to produce glucose. It takes place in the stroma of the chloroplast.

The light reaction takes place in the thylakoid discs. There, water (H20) is oxidized, and oxygen (O2) is released. The electrons freed up from water are transfered to ATP and NADPH. The dark reaction occurs outside of the thylakoids.

: any of a series of chemical reactions in photosynthesis not requiring the presence of light and involving the reduction of carbon dioxide to form carbohydrate especially : calvin cycle.