(d) : Krebs' cycle is intimately related with fat metabolism. Dihydroxy acetone phosphate produced in glycolysis may be converted into glycerol via glycerol - 3 - phosphate and vice-versa. Glycerol is important constituents of fats. After β -oxidation, fatty acids give rise to active 2 -C units, the acetyl-CoA which may enter the Krebs' cycle. Thus, Acetyl-CoA is a link between glycolysis, Krebs' cycle and β -oxidation of fatty acid or carbohydrate and fat metabolism.