Where does fatty acid synthesis primarily occur in cells?

✅Explanation: Fatty acid synthesis primarily takes place in the cytoplasm of cells, specifically in the cytosol. This process involves the enzyme acetyl-CoA carboxylase and fatty acid synthase, which work together to build fatty acids from acetyl-CoA and malonyl-CoA molecules.

📌📌Other Options:
-Mitochondria: Involved in energy production (ATP), beta-oxidation of fatty acids (breakdown).
-Chloroplast: In plants, involved in photosynthesis and some specialized fatty acid synthesis.
Important Points
-Lipids are polymers made up of fatty acids and glycerol.
-Fatty acids are organic acids with hydrocarbon side chains ending in a carboxylic group (-COOH).
-The hydrocarbon side chain may be straight or have a ring structure.
-Fatty acids are obtained from the hydrolysis of fats.
-There are two types of fatty acids – 

• Saturated:
-​Do not possess double bonds in the carbon chain.
-E.g.: Palmitic acid [C16H32O2]

• Unsaturated:
-Presence of one or more double bonds in the carbon chains.
-E.g.: Linoleic acid [C18H32O2 – two double bond]

• Biosynthesis of fatty acids:
-Fatty acid synthesis takes place in the endoplasmic reticulum and cytoplasm.
-Fatty acids are synthesized in most living organisms including humans from non-lipid substances.
-The building material from which fatty acids are synthesized is Acetyl CoA.
-Carbohydrates and proteins can be metabolically degraded to Acetyl CoA. Thus they can be precursors for fatty acid formation.
-From the Krebs cycle which is a part of the respiratory mechanism in aerobic organisms, acetyl CoA is used as a precursor for the synthesis of fatty acid.
-Fatty acid synthesis involves joining together acetyl CoA units to form long carbon chain molecules.
-It employs different enzymes, ATP, NADPH, coenzyme A, vitamin B12 and biotin.
-Thus from the above-given information, the compound that will be withdrawn from the respiratory pathway for the synthesis of fatty acid is Acetyl CoA.