acetyl CoA pathway

The acetyl CoA pathway is also called the Wood Ljungdahl Pathway. The acetyl-CoA pathway comprises two reductive branches, the methyl branch and the carbonyl branch, both of which reduce CO2 and fix CO2-derived carbon into covalently bonded forms.

The pathway allows bacteria to grow on sugars or on H2/CO2 :
4H2 + 2 CO2 = CH3COOH + 2 H2O
4H2 + 2 CO2 = CH3COOH + 2CO.

Althought the acetyl-CoA pathway can be presented in a cyclic form (Wood and Ljungdahl), it is a linear process that does not depend on multi-carbon intermediates to which CO2 is fixed in a cyclic fashion. For example, the Calvin (C-3) cycle is a CO2-fixing processes that depends upon ribulose biphosphate for the initial fixation of CO2, and the reductive (reverse) tricarboxylic acid cycle depends upon oxalacetate for the initial fixation of CO2. Although the cofactors and electron carriers of the acetyl-CoA pathway pathway cycle between different states, the pathway itself is linear relative to carbon flow.

AcetylCoA and acetacetylCoA: amino acids : mnemonic:"A Lighter Lease" (A LyTr LeIs): A=AcetylCoA or Acetoacetyl CoA Ly=Lysine Tr=Tryptophan Le=Leucine Is=Isoleucine

external table - enzymes of Acetyl CoA pathways : Saccharomyces cerevisiae carbon monoxide dehydrogenase pathway : Arabidopsis thaliana carbon monoxide dehydrogenase pathway : MetaCyc reductive acetyl coenzyme A pathway :


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