The importance of light in photosynthesis is immense. For the production of carbohydrates from H2O and CO2. the source of the required energy is light. Sunlight also takes part in the development of chlorophyll. With sunlight and when stomata are open, CO2 can enter the leaves, and take part in the production of food. The rate of photosynthesis increases with the increase of light up to a definite limit.
Energy is released from the photosynthesis process generated by foods through respiration. Usually, this energy is stored within ATP in the bond of the terminal phosphate group. When this bond is broken, energy is released, which can be used in different physicochemical reactions.
Biological currency refers to a molecule or substance that is used as a common means of exchange in metabolic processes within cells. The most well-known example of a biological currency is ATP (adenosine triphosphate), which acts as the primary source of energy for cellular processes in all living organisms.
In cells, ATP is synthesized from other molecules through metabolic pathways, and it can then be used as an energy source by enzymes to drive cellular processes, such as muscle contraction, ion transport, and biosynthesis. When ATP is broken down, energy is released, which can be used to drive other cellular processes.
In this way, ATP acts as a "currency" that can be exchanged for energy between different metabolic pathways within the cell. Other biological currencies exist as well, depending on the organism and the metabolic processes in question. For example, NADH (nicotinamide adenine dinucleotide) is used as a source of energy in cellular respiration, while cyclic AMP (cAMP) acts as a second messenger in signal transduction pathways.