Answer: The correct answer is option d
Explanation:
Nucleotide is the basic unit of nucleic acid (DNA and RNA) which store the genetic code of the cell.
It consists of sugar base (ribose or deoxyribose), nitrogenous base (A, T, G, C and U), and phosphate group.
Nucleotides (specially ATP) provides the energy for most of the cellular processes.
They also play crucial role of providing electrons to the electron transport chain. For example, NADH (Nicotinamide adenine dinucleotide- reduced form) and FADH₂ (flavin adenine dinucleotide- reduced form).
However, there is no significant role of nucleotide has been found for providing substrates to citric acid cycle.
Therefore, the correct answer is option d, rest all are the functions of nucleotide.
