Nucleotide — Overview & Structure

Nucleotide Structure

Nucleic acids are made up of basic building blocks called nucleotides. Each one has three parts.

1: A 5-carbon sugar molecule (the big pentagon)

• DNA: deoxyribose
• RNA: ribose
• ATP: ribose

2: A phosphate group (the part with a phosphorous atom)

• RNA and DNA: the phosphate group binds to another nucleotide's carbon ring, forming the backbone of the molecule
• ATP: there are three phosphates in the phosphate group that store energy

3: A nitrogenous base (the nitrogenous base always has a nitrogen)

• DNA: the nitrogenous bases are adenine, guanine, cytosine, and thymine
• RNA: the nitrogenous bases are adenine, guanine, cytosine, and uracil
• ATP: the nitrogenous base is always adenine

This is an ATP molecule. It is different from DNA and RNA because it has three phosphate groups instead of one. The two additional phosphate groups are what allow ATP molecules to store so much energy. The nitrogenous base is the group emerging from the carbon ring that has five nitrogen atoms attached to it. This particular nitrogenous base is adenine.

Building Blocks of Nucleic Acids

Nucleic acids are polymers made from building blocks called nucleotides.

Nucleotides are made up of a nitrogen group (called a nitrogenous base), a phosphorus group, and a 5-carbon ring. These monomers join together by covalent bonds to form nucleic acids.

Nucleotide monomers and the unique nitrogenous bases create the framework for all the genetic information in a living organism. These bases form chemical bonds with their complementary base pairs in DNA (deoxyribonucleic acid) to form double-stranded molecules that are necessary for encoding an organism's genetic information.

Nucleotides are important in gathering and transferring chemical energy. An example that we'll learn more about later is adenosine triphosphate (ATP). It is often called the "molecular unit of currency".

$$\color{#8925AE}{\text{Vocabulary Review:}}$$

$\color{#8925AE}{\text{Monomer}}$ : Any molecule that can react with other molecules of the same or different makeup to form a chain, or polymer

$\color{#8925AE}{\text{Polymer}}$ : A chain of monomers made of a specific type of compound

$\color{#8925AE}{\text{Macromolecule}}$ : A polymer that has a large (macro) molecular mass. There are four main types in organisms: carbohydrates, proteins, lipids, and nucleic acids

$\color{#8925AE}{\text{Nucleotides}}$ : The monomers of nucleic acids. Made up of a nitrogen group, a phosphorus group, and a 5-carbon ring

$\color{#8925AE}{\text{Nucleic Acid}}$ : Complex polymer that stores information in a cell in the form of a code. DNA and RNA

(Video) DNA, Nucleotides, and Dehydration Synthesis

by Johnny Clore

This video dives into what makes up a nucleotide. In other words, what makes up the monomers that make up nucleic acids. Plus, you'll learn how these monomers come together to form long chains of polymers.