Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What is the primary function of a nucleotide?

1. To act as a source of energy for cellular processes

2. To serve as the basic building block of nucleic acids

3. To facilitate cell signaling between different parts of the body

4. To code for amino acids during protein synthesis

The correct answer is: To serve as the basic building block of nucleic acids

The primary function of a nucleotide is to serve as the basic building block of nucleic acids, specifically DNA and RNA. Nucleotides play a crucial role in the structure of these macromolecules, as they consist of a nitrogenous base, a sugar, and a phosphate group. These components combine to form long chains that store and convey genetic information. Each nucleotide's sequence along a strand of DNA or RNA ultimately determines the genetic instructions for building proteins, which are vital for the structure and function of living organisms. While other options do touch upon important cellular functions, they do not accurately represent the core role of nucleotides. For example, some nucleotides can indeed have roles in cellular energy transfer, such as ATP, but their fundamental identity is tied to their role in nucleic acids. Similarly, while some nucleotides can assist in signaling pathways, that is not their primary function; rather, it is a secondary role that varies based on the specific nucleotide. Lastly, while nucleotides are critical in the coding and transmission of genetic information, the act of coding for amino acids is ultimately performed by the sequences of nucleotides within the nucleic acids rather than by the nucleotides themselves. Therefore, the most accurate answer