This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nucleotides, Subject name: Biochemistry
Nucleotides serve all of the following roles, EXCEPT: 
Select and explain. 
A. Monomeric units of nucleic acids, B. Mediators in cellular signalling, C. Source of energy, D. Structural component of membrane
D: Structural component of membrane
Answer: D: Structural component of membrane 
Explanation: Nucleotide Nucleic acids are polynucleotides CAMP and cGMP are cyclic nucleotides involved in signaling pathways. ATP is the cellular currency of energy Membrane is made up of phospholipids and cholesterol and not nucleotides.