The key difference between phosphodiester bond and phosphoester bond is that phosphodiester bond forms when a sugar molecule binds with a phosphate group and a hydroxyl group whereas a phosphoester bond forms when a sugar molecule binds with a phosphate group.
Phosphoester and phosphodiester bonds are common in biochemical molecules. Phosphodiester bond is the linkage between monosaccharides in carbohydrate molecules.
CONTENTS
1. Overview and Key Difference
2. What is Phosphodiester Bond
3. What is Phosphoester Bond
4. Side by Side Comparison – Phosphodiester Bond vs Phosphoester Bond in Tabular Form
5. Summary
What is Phosphodiester Bond?
Phosphodiester bond is a biochemical bond that forms when two of the hydroxyl groups in the phosphoric acid reacts with hydroxyl groups on the other molecule(s) to form two ester bonds. The prefix “-di-“ in this term refers to “two” so, it indicates that this type of chemical bond has two ester linkages per phosphodiester bond.
We can say that phosphodiester bonds are central to all life on Earth because these bonds make up the backbone of nucleic acid strands such as DNA and RNA. In these DNA and RNA molecules, phosphodiester bond is the linkage between the third carbon atom of a sugar molecule and the fifth carbon atom of an adjacent sugar molecule. In DNA molecules, deoxyribose is the sugar molecule while in RNA, it is ribose sugar. Here, a strong covalent bond forms between the phosphate group and sugar molecules over two ester bonds.
Figure 01: Phosphodiester Bonds Between Sugar Molecules
When forming a phosphodiester bond to join the nucleotides with each other, the tri-phosphate or the di-phosphate molecules of the nucleotide building blocks are broken apart, giving off an energy that is required to drive the enzyme-catalyzed reaction. Here, the phosphodiester bond forms when a single phosphate or two phosphates break away, catalyzing the chemical reaction.
What is Phosphoester Bond?
A phosphoester bond is a type of chemical bond that forms when a sugar molecule binds with a phosphate group. The resulting bond occurs between O-C atoms because the hydroxyl groups of the phosphate group and sugar molecule react with each other through transesterification. Here, the OH- group from the sugar molecule leaves only the oxygen atom, releasing hydrogen atom, and it is the oxygen atom of the –P-O-C- bond.
What is the Difference Between Phosphodiester Bond and Phosphoester Bond?
Phosphoester and phosphodiester bonds are common in biochemical molecules. Phosphodiester bond is the linkage between monosaccharides in carbohydrate molecules. Phosphodiester bond is a biochemical bond that forms when two of the hydroxyl groups in the phosphoric acid reacts with hydroxyl groups on another molecule(s) to form two ester bonds while a phosphoester bond is a type of chemical bond that forms when a sugar molecule binds with a phosphate group. Therefore, the key difference between phosphodiester bond and phosphoester bond is that phosphodiester bond forms when a sugar molecule binds with a phosphate group and a hydroxyl group whereas a phosphoester bond forms when a sugar molecule binds with a phosphate group.
The following infographic summarizes the difference between phosphodiester bond and phosphoester bond in tabular form.
Summary – Phosphodiester Bond vs Phosphoester Bond
Phosphoester and phosphodiester bonds are common in biochemical molecules. Phosphodiester bond is the linkage between monosaccharides in carbohydrate molecules. The key difference between phosphodiester bond and phosphoester bond is that phosphodiester bond forms when a sugar molecule binds with a phosphate group and a hydroxyl group whereas a phosphoester bond forms when a sugar molecule binds with a phosphate group.
Reference:
1. “13.10: Phosphoester Formation.” Libretext, Available here. 11 Aug. 2020.
Image Courtesy:
1. “Phosphodiester Bond Diagram” By File:Enlace fosfodiéster.png, File:PhosphodiesterBondDiagram.png: User:G3pro (talk)Original uploader was User:G3pro at en.wikipedia.orgDerivative work: User:Merops (talk)Derivative work: User:Deneapol (talk)Derivative work: User:KES47 (talk)Text tweaks: Incnis Mrsi (talk)Text tweaks: DMacks (talk))Derivative work: User:Miguelferig (talk) with ionizationChem. / graphical improvements: User:Mykhal (talk) – File:Enlace fosfodiéster.png (CC BY-SA 3.0) via Commons Wikimedia