In the process of lipogenesis, the fatty acids are formed by several addition (condensation) reaction of thetwo – carbon acetyl units up to 16 carbon atoms.Fatty acids oxidation occurs in the mitochondria and it utilizes the oxidizing enzymes FAD and NAD+ while the fatty acid synthesis occurs in the cytosol and utilizes the reduced enzyme NADPH.The fatty acids synthesis is shown below: |
Reference: https://bio.libretexts.org/Bookshelves/Biochemistry/Book%3A_Biochemistry_Free_and_Easy_(Ahern_and_Rajagopal)/06%3A_Metabolism_I_-_Oxidative%2F%2FReductive_Processes/6.12%3A_Fatty_Acid_Synthesis |
Note that ACP stands for Acyl Carrier Protein is used to activate acetyl groups. HS-ACP has a thiol group and pantothenic acid (vitamin B5) groups in the coenzyme A. These groups are attached to the protein chain skeleton rather than to the adenosine group.Coenzyme A: |
Reference: https://www.lipidhome.co.uk/lipids/simple/coA/index.htm |
Reference: https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/acyl-carrier-protein |
The preparation of acyl and acetyl activated groups can be utilized through the reactions discussed below: |
Reference: https://slideplayer.com/slide/5840252/ |
Synthesis of Fatty acid (palmitic acid): |
The synthesis undergoes 4 reactions steps shown in the figure below:CondensationReductionDehydrationReduction |
Reference: https://dennisnderitu.wordpress.com/2016/07/14/fatty-acid-synthesis-activation-steps-and-control/ |
The videos below illustrate the fatty acids synthesis: