Select All of the Following That Are Components of Nucleotides

Three components make up every nucleotide: a phosphate group, a five-carbon sugar, and a nitrogenous base. So if you’re asked to select all of the following that are components of nucleotides, those three are the answers—phosphate, sugar, and base. Anything else (amino acids, fatty acids, glycerol) belongs to different molecules entirely.

The Three Building Blocks

A nucleotide is essentially a sugar with a phosphate on one side and a base on the other. The National Human Genome Research Institute describes a nucleotide as the basic building block of nucleic acids, and it consistently lists these same three parts.

• Phosphate group — a phosphorus atom bonded to four oxygen atoms. It links nucleotides together into a backbone and gives DNA and RNA their overall negative charge.
• Five-carbon sugar (pentose) — deoxyribose in DNA, ribose in RNA. The only difference between them is an oxygen atom at the 2′ position: deoxyribose lacks the hydroxyl group that ribose has.
• Nitrogenous base — the information-carrying part. DNA uses adenine (A), thymine (T), cytosine ©, and guanine (G). RNA swaps thymine for uracil (U).

If an answer choice is one of those three, select it. Amino acids, glycerol, and fatty acids are common distractors but are not nucleotide components.

How the Pieces Connect

The base attaches to the 1′ carbon of the sugar, and the phosphate attaches at the 5′ carbon. When nucleotides join, the phosphate of one links to the sugar of the next, forming the sugar-phosphate backbone that Nature Scitable describes as the structural framework of DNA and RNA.

Here’s a quick worked example. Take the nucleotide adenosine monophosphate (AMP). It contains adenine as its base, ribose as its sugar, and a single phosphate group—all three components in one molecule.

Key Takeaways

• A nucleotide has exactly three components: a phosphate group, a five-carbon sugar, and a nitrogenous base.
• DNA uses deoxyribose; RNA uses ribose. DNA uses thymine; RNA uses uracil.
• Amino acids, glycerol, and fatty acids are not nucleotide components—they’re common wrong answers.
• The sugar-phosphate backbone links nucleotides together, while the bases carry the genetic code.