Metabolic pathway
In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell, catalyzed by enzymes, and resulting in either the formation of a metabolic product to be used or stored by the cell (metabolic sink), or the initiation of another metabolic pathway (then called a flux generating step).
Overview
Most metabolic pathways have these common properties:
- They are irreversible, usually because the first step is a committed step that only runs in one direction.
- The pathways are regulated, usually by feedback inhibition.
- Anabolic and catabolic pathways in eukaryotes are separated by either compartmentation or by the use of different enzymes and cofactors.
Major metabolic pathways
Cellular respiration
Main article: Cellular respiration
Several distinct but linked metabolic pathways are used by cells to transfer the energy released by breakdown of fuel molecules to ATP:
Other pathways
- Fatty acid oxidation (beta oxidation)
- Gluconeogenesis
- HMG-CoA reductase pathway (cholesterol, isoprene prenylation chains)
- Pentose phosphate pathway (hexose monophosphate shunt)
- Porphyrin synthesis (or heme synthesis) pathway
- Urea cycle
See also
External links
- Google directory (http://directory.google.com/Top/Science/Biology/Biochemistry_and_Molecular_Biology/Metabolic_Pathways/)
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