What are nucleosides, nucleotides, and nucleic acids?

This post is about nucleosides, nucleotides, and nucleic acids. It is often confusing for students to remember and tell the differences between them.

Let's look at what they are.

A nitrogenous base, sugar, which can be either deoxyribose or ribose sugar, and phosphate are building blocks of nucleic acids, DNA, and RNA.

Nitrogenous bases are

Adenine,

Guanine,

Cytosine,

Thymine,

and Uracil

Among these bases, Adenine and guanine are known as Purines.

Similarly, Cytosine, Uracil, and Thymine are Pyrimidines.

How to remember them?

The Mnemonic is "Pure as gold." for purines and C, U, T, for pyrimidines.

When these bases are combined with sugar, they are then known as nucleosides, "Remember sides with sugar!"

Nucleosides have names either ending in "sines" or "dines"

Adenosine,

Guanosine,

Cytidine,

Thymidine,

Uridine.

When phosphate is added to nucleosides, it gives nucleotides.

Remember "Tides with Phosphate"

These can be monophosphate, diphosphate, or triphosphate. for example: Adenosine monophosphate, Cytidine Diphosphate, Uridine Triphosphate, etc.

Oh, wait, What are DNA and RNA?

When these Different Nucleotides connect by phosphodiester bonds and form a polymer, they are called nucleic acids.

DNA and RNA are two types of nucleic acids.

Sugar is deoxyribose in DNA and ribose in DNA.

Remember, Uracil is found in RNA and Thymine in DNA.

Bonds formed between Nitrogenous bases hold the double helix of DNA together.

Remember AT(or U in RNA), CG. That means Adenine bonds with Thymine or Uracil by double bonds. Similarly, Cytosine forms a bond with Guanine, by triple hydrogen bonds. Therefore higher CG content makes stronger bonds, which makes it harder to denaturate.

This concludes our review. Thank you. See you in the next post!

You can review this in the video lesson below :

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