Question

Germinating plant seeds can convert acetyl-CoA (obtained from fatty acids stored as oils) into carbohydrates, whereas animals are incapable of converting fatty acids into glucose. Explain why this is so.

Answer 1

Answer:

Germinating plant seeds can convert acetyl-CoA into carbohydrates whereas animals are incapable of converting fatty acids into glucose due to the fact that plants use glyoxylate cycle.

Glyoxylate cycle in plants is a variation of TCA cycle in animals and this cycle involves the conversion of acetyl-CoA to succinate which is used for the biosynthesis of carbohydrates. 2 acetyl-CoA molecules are involved in the production of 1 succinate molecule.

Isocitrate lyase and malate synthase are two critical enzymes of the glyoxylate cycle whereas vertebrate lacks these enzymes.