Write few lines on photosynthesis
Answers
It is the process by which green plant and some other organism use sunlight to synthesize nutrients from carbon dioxide and water.
The main product form here is glucose and by products are oxygen and water.
Here it takes place in chlorophyll and I'm presence of sunlight.
There are two stages of photosynthesis :
1. Light reactions :
It occurs in the grana where photon are absorbed so as to excite electrons of chlorophyll to a higher energy level. These activated elctrons are harnessed to form ATP from the ADP and reduce NADP to NADPH. Wayer ia also spotted here and oxygen is released.
2. Dark reactions :
Calvin cycle occurring in chlorophyll here carbon combine with 5-carbon sugar called ribulose biphospahte. This unstable compound breaks down into 3-carbon compound. This then forms glucose.
Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant.
Overall equation for the type of photosynthesis that occurs in plants
Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in the ocean and on land, respectively.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities (energy transformation). This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις, synthesis, "putting together".[1][2][3] In most cases, oxygen is also released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies all of the organic compounds and most of the energy necessary for life on Earth.[4]
Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting of water is used in the creation of two further compounds that serve as short-term stores of energy, enabling its transfer to drive other reactions: these compounds are reduced nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells.
In plants, algae and cyanobacteria, long-term energy storage in the form of sugars is produced by a subsequent sequence of light-independent reactions called the Calvin cycle; some bacteria use different mechanisms, such as the reverse Krebs cycle, to achieve the same end. In the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate (RuBP).[5] Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates, such as glucose.