Arginine biosynthesis starts with glutamate as the precursor (the called "glutamate family") from where also proline and ornithine come from. The precursor of Arginine biosynthesis from glutamate - proline biosynthesis pathway is an intermediate compound, the glutamate-5-semialdehyde that is transaminated by the enzyme ornithine-delta-aminotransferase to form an ornithine molecule. On the other hand, glutamate can form ornithine through another way, first, the formation of N-Acetylglutamate (catalyzed by the enzyme N-acetylglutamate synthase) that is phosphorylated by ATP, catalyzed by the acetylglutamate kinase enzyme, to form N-Acetylglutamate-5-phosphate. This intermediate form N-Acetylglutamate-5-semialdehyde by the enzyme N-acetyl-gamma-glutamyl phosphate dehydrogenase in the presence of NAD(P)H. The next step is the formation of N-Acetylornithine catalyzed by the enzyme N-acetylornithine-delta-aminotransferase. Finally, ornithine is formed by the catalysis of the enzyme acetylornithine deacetylase. In both cases, an ornithine compound that goes to the urea cycle, that occurs partially in the mitochondrion and partially in the cytosol. In the urea cycle, ornithine is transported across the mitochondrial membrane by a specific transport system and converted to citrulline by an ornithine transcarbamoylase. Citrulline leaves the mitochondrion by a specific transport through the mitochondrial membrane and converted into Argininosuccinate by the enzyme argininosuccinate synthase. The latter compound is transformed into Arginineby the loss of fumarate molecule and catalyzed by the enzyme arginase.
Feedback Inhibition
krebs cycle
This phenomenon is known as feedback inhibition, where the final product of a biochemical pathway binds to the enzyme responsible for an early step in the pathway, inhibiting its activity. This mechanism helps regulate the overall rate of the pathway, ensuring that the cell does not produce excessive amounts of the final product.
They both are a series of linked reactions.
Cori Cycle
Photosynthesis is referred to as a biochemical pathway because it involves a series of chemical reactions that occur within plant cells. These reactions convert light energy into chemical energy stored in the form of glucose. The process is highly regulated and involves multiple steps that are catalyzed by specific enzymes.
Fermentation
The slowing or stopping of an early reaction in biochemical pathway when levels of the end product become high is to stimulate electron transport chain. Electron transport chain is a series of linked chemical reactions.
biochemical pathway
Because several biochemical reactions governed by specific enzymes take place from photolysis of water to the formation of carbohydrates by assimilation of CO2.
This metabolic pathway comes under anabolism and all biochemical reactions unitedly called photosynthesis.
Albert Szent-Györgyi received the Nobel Prize in Physiology or Medicine in 1937 for his discoveries on vitamin C and the citric acid cycle, key components of the biochemical pathway that produces glucose.