Phosphodiester Bond: Definition, Formation, Importance

Phosphodiester bond means the formation of two ester bonds when two hydroxyl groups (OH) of phosphoric acid (H3PO4) react with two hydroxyl groups (OH) of other molecules. This results removal of water between the molecules which causes the formation of bonds.

It is vital to know the chemistry of phosphodiester bonds because it is responsible for holding the backbone of DNA and RNA in an animal body. They are covalently bonded and formed by the sharing of electrons between the atoms of molecules.

Formation of phosphodiester bond

A phosphodiester bond is formed when the phosphate group reacts with molecules. For example, two nucleotides are attached to each other with the help of a phosphodiester bond.

A nucleotide is composed of three components, such as ribose sugar, a phosphate group, and a nitrogenous base.

One hydroxyl group (OH) of phosphate bonded with the 3-carbon atom of sugar in the first nucleotide. Similarly, the second hydroxyl group of the same phosphate group bonded with the 5-carbon atom of ribose sugar in the second nucleotide.

phosphodiester bond

This reaction is known as the condensation reaction. It is because water is removed when the hydroxyl group (OH) of phosphate gives hydrogen (H) and ribose sugar releases the one complete hydroxyl group (OH). In this way, two hydrogens atoms and one oxygen atom combine to give water (H2O) during the reaction.

Phosphodiester Linkage

DNA and RNA are composed of strands of nucleotides. These nucleotides are bonded with each other in the form of a series known as polymers. A single strand of DNA contains polymers of nucleotides which are formed by monomers of nucleotides. These monomers are bonded together with the help of phosphodiester bonds. They are joined in the form of a long chain or a linage due to phosphodiester bonds called phosphodiester linkage.

Biological importance of phosphodiester bond

DNA and RNA have important roles to maintain human life. DNA is a double-stranded structure and stands for deoxyribonucleic acid. On the other hand, RNA stands for ribonucleic acid which is a single-stranded structure.

DNA is a blueprint of human life that stores data and transfers it to the next generation. While RNA is a genetic material that is responsible for making protein. Both are nothing with phosphodiester bonds. It is because phosphodiester bonds maintain the structure of DNA and RNA.

Phosphodiester bonds are negatively charged. They repel each other which influences the conformation of polynucleic acid. This negatively charged molecule attracts the protein histones and metal ions, such as magnesium, and polyamines that are positively charged.

Concepts Berg

Are phosphodiester bonds covalent?

Yes, they are covalently bonded. They shared electron pairs of atoms in molecules.

How many phosphodiester bonds are in DNA?

There are 18 phosphodiester bonds in one turn of DNA.

How are phosphodiester bonds formed in DNA?

Phosphodiester bonds are formed when hydroxyl groups of phosphate react with the hydroxyl group of the sugar. Water is eliminated as the result of the reaction.

Do phosphodiester bonds link nucleotides?

Yes, they linked the nucleotides monomers and formed nucleotide polymers.

What type of bond is a phosphodiester bond?

A phosphodiester bond is an ester bond that is formed between phosphoric acid and ribose sugar.

Is a phosphodiester bond a hydrogen bond?

No, it is not a hydrogen bond. It is covalent in nature.

Does ATP have phosphodiester bonds?

Adenine triphosphate (ATP) does not contain phosphodiester bonds. Instead, they are composed of phosphoanhydride bonds.

What are chemical bonds in DNA?

Phosphodiester bonds act as the backbone of DNA. These are the chemical bonds in DNA.

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