The Metabolic pathway reference article from the English Wikipedia on 24-Jul-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Metabolic pathway

In biochemistry, a metabolic pathway is a series of chemical reactions within a cell, catalyzed by enzymes, which either results in the formation of a product to be used/stored by the cell (metabolic sink), or the initiation of another metabolic pathway (also called flux generating step).

Table of contents

1 Overview 2 Major metabolic pathways 2.1 Cellular respiration 2.2 Other pathways 3 See also 4 External links

Overview

Most metabolic pathways have 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:

1. Glycolysis
2. Anaerobic respiration
3. Krebs' cycle
4. Oxidative phosphorylation

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

• catabolism

External links

• Google directory

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