Q.

What is the role of NAD+ in cellular respiration                       [2018]

1 It functions as an enzyme.  
2 It functions as an electron carrier.  
3 It is a nucleotide source for ATP synthesis.  
4 It is the final electron acceptor for anaerobic respiration.  

Ans.

(2)

NAD+ is a coenzyme and an electron carrier. It acts as an electron acceptor in glycolysis and Kreb’s cycle through dehydrogenation processes and is then reduced to NADH. NAD+ acts as an electron carrier which is later used to generate proton gradient across the inner mitochondrial membrane and produce energy in the form of ATP.