In a broader sense, photosynthesis, including CO2 anabolism, can be divided into several steps: i) photoelectric charge isolation using photon energy (conversion to electrical energy), ii) fixation of electrical energy in the form of chemical energy (ATP synthesis), and iii) chemical reactions involving ATP (fixation of CO2, and hydrogen production).
Metabolism refers to all of the chemical processes in a cell. It is usually divided into two categories: catabolism and anabolism. Cellular respiration is an example of catabolism, whereas photosynthesis is an anabolic process.
While most people think of plants when photosynthesis is mentioned, algae actually undergo much more photosynthesis than plants. It has been estimated that about 90% of the oxygen produced from photosynthesis comes from algae and phytoplankton living in oceans. Plants, protists, and even some bacteria undergo photosynthesis.
Photosynthesis is the conversion of light energy intochemicalenergy that can be used in the formation of cellular material from CO2.Photosynthesis is a type of metabolism separable into a catabolic andanaboliccomponent. The catabolic component of photosynthesis is the lightreaction,wherein light energy is transformed into electrical energy, thenchemicalenergy. The anabolic component involves the fixation of CO2and its use as a carbon source for growth, usually called the darkreaction.In photosynthetic procaryotes there are two types of photosynthesis andtwo types of CO2 fixation.
What is metabolism?
All living things must have an unceasing supply of energy and matter. The transformation of this energy and matter within the body is called metabolism. Metabolism includes two different types: catabolism and anabolism. Catabolism is destructive metabolism. Typically, in catabolism, larger organic molecules are broken down into smaller constituents. This usually occurs with the release of energy. Anabolism is constructive metabolism. Typically, in anabolism, small precursor molecules are assembled into larger organic molecules. This always requires the input of energy.
Anabolism and catabolism Pathways
Anabolism is the synthesis of complex molecules from precursors. This includes synthesis of proteins, carbohydrates, nucleic acids and lipids, usually from their building block monomers. Catabolism is the breakdown of complex molecules into smaller precursors from which they are synthesized. It is a reversed process of anabolism. When cells have excess resources such as food and extra energy, anabolism occurs to store unused nutrients for later use. When cells are deficient for food or energy, catabolism occurs to break down the stored nutrients for the body to use.
Metabolism includes catabolism and anabolism. Anabolism is the synthesis of complex molecules from precursors, while catabolism is the breakdown of complex molecules into smaller precursors from which they are synthesized. All these pathways involve biochemical reactions. Free energy describes whether a reaction will occur spontaneously. In metabolism, reactions which are spontaneous are favorable because these run automatically and release free energy. Every reaction has an activation energy which can be lowered down by enzymes. Enzymes do this by bringing the reactants closer together. ATP is the energy currency of all cells. Most of the reactions in the cell require ATP. A non-spontaneous reaction can be coupled to ATP hydrolysis reaction to enable the overall reaction release free energy and therefore become favorable. ATP is generated by cellular respiration, which contains fermentation (anaerobic respiration) and the Krebs cycle (aerobic fermentation).
The efficiency of the latter reaction can be determined by multiplying the efficiency of CO2; anabolism by the efficiency of hydrogen production in photosynthetic bacteria.