The world is full of cellulose. Cellulose is the stuff plants are made of. It is a kind of sugar or carbohydrate that we cannot eat. These are stored in chain like structures called lignins.
Cellulose contains the basic building blocks of life Carbon, Oxygen, Hydrogen, Nitrogen and a few metals like phosphorus, calcium, and boron.
How do plants make cellulose? They do so through a way called photosynthesis. We can call it solar cooking.
The greenery around us is not there without a reason. The green material is Chlorophyll, a protein that helps to absorb light energy from the sun.
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.
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.
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.
Role of bio-protiens.
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 to nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the energy bearers of cells.
The first photosynthetic organisms evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulfide, rather than water, as sources of electrons.
Cyanobacteria appeared later; the excess oxygen they produced contributed directly to the oxygenation of the Earth, which rendered the evolution of complex life possible. Today, the average rate of energy capture by photosynthesis globally is approximately 130 terawatts, which is about three times the current power consumption of human civilization. Photosynthetic organisms also convert around 100–115 billion tonnes (91-104 petagrams) of carbon into biomass per year.