Question

1.in which step is water used in photosynthesis?
2.what form of energy powers light-dependent reaction of photosynthesis?
3.what form of energy powers the light independent reaction of photosynthesis?
4.is photosynthesis an endothermic or an exothermic reaction?
5.what must happen at the end of the light-dependent reaction in order for the light-independent reaction to be able to occur? (what energy molecules are
echarged\?)

Explanation:

1. Water is split in the light-dependent reactions to release electrons, hydrogen ions, and oxygen.
2. Light-dependent reactions rely on sunlight to excite electrons in chlorophyll.
3. Light-independent reactions use chemical energy stored in molecules produced in the light-dependent stage.
4. Photosynthesis absorbs energy from sunlight to build glucose, so it takes in energy.
5. The light-dependent reactions generate energy-carrying molecules that fuel the light-independent Calvin cycle.

Answer:

1. Water is used in the light-dependent reactions (specifically in photolysis, where it is split to provide electrons, H⁺ ions, and oxygen).
2. Light energy (sunlight)
3. Chemical energy (stored in ATP and NADPH)
4. Endothermic
5. ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate) must be produced (recharged) to power the light-independent reaction.