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Information About

Metabolic Pathway





Metabolism is a step by step modification of the initial molecule to shape it into another product. The result can be used in one of three ways.
  • Stored by the cell.

  • Be used immediately, as a metabolic product.

  • Initiate another metabolic pathway, called a flux generating step.


A molecule called a Substrate enters a metabolic pathway depending on the needs of the cell & the availability of the substrate. An increase in concentration of Anabolical and Catabolical end products would slow the metabolic rate for that particular pathway.


OVERVIEW


Metabolic pathways often have these properties:
  • They contain many steps, like a cascade. The first step is usually irreversible. The other steps need not be irreversible and in many cases, the pathway can go in opposite direction depending on the current need of the cell.

  • Glycolysis features excellent examples of these features:

  • :#As Glucose enters a cell it is immediately Phosphorylated by ATP to Glucose 6-phosphate in the irreversible first step. This is to prevent the glucose leaving the cell.

:#In times of excess Lipid or Protein energy sources Glycolysis may run in reverse ( Gluconeogenesis ) in order to produce Glucose 6-phosphate for storage as Glycogen or Starch .


MAJOR METABOLIC PATHWAYS








Cellular respiration

See Also: Cellular respiration



Several distinct but linked metabolic pathways are used by cells to transfer the energy released by breakdown of Fuel Molecule s to ATP . These occur within all living organisms in some forms:
# Glycolysis
# Anaerobic Respiration
# Krebs Cycle / Citric Acid Cycle
# Oxidative Phosphorylation

Other pathways occurring in (most or) all living organisms include:

Creation of energetic compounds from non-living matter:


SEE ALSO



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