Question

172. Electrons extracted from fatty acids in the peroxisomes are transferred to __________________.
A.   NAD+
B.   molecular oxygen
C.   cytochrome C
D.   Quinones

173. Gluconeogeneis is _________________.
A.   The exact opposite of glycolysis.
B.   More energetically favorable than glycolysis.
C.   Energetically more costly than glycolysis.
D.   The amount of energy to perform gluconeogenesis is equal to the amount of energy in metabolizing glucose.

Answer 1

172. Ans. NAD+

Explaination: During beta-oxidation of fatty acids, electrons from oxidation of fatty acids are transferred to NAD+ and FAD resulting into the formation of NADH and FADH2 . These NADH and FADH2 enter into electron transport system (ETS) to generate energy i.e. ATP.

173. Ans. Energetically more costly than glycolysis.

Explaination: Gluconeogenesis involves the formation of glucose from non-carbohydrate precursors. For each pyruvate molecule to form glucose, it requires two ATP molecules, one GTP molecule and one NADH molecule. But in case of glycolysis which is the breakdown of glucose into two pyruvate nolecules, here each glucose molecule requires only two molecules of ATP. Glycolysis is not exactly the reverse process of gluconeogenesis in terms of enzymes and energy requirements even though it is formally considered a opposite process of glycolysis.