What nucleic acid subunits are connected in a phosphodiester linkage in a polynucleotide?

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All right. Hello everyone. So this question is asking us the formation of which bond is crucial for linking nucleotides together during the synthesis of a polynucleotide chain option. A is glyco cytic bond. B says hydrogen bond C says phospho aster bond and D says peptide bond. So recall first and foremost that nucleotides are the monomers of nucleic acids, right? That is DNA or RN A and any given nucleotide has three main components to consider. So the first is the sugar backbone, which is more or less in the center of the structure. And so attaching to the sugar backbone is a nitrogenous base as well as a phosphate group. Now recall that when it comes to making a polynucleotide chain, it's the phosphate group and the sugar backbone that are being connected. And so to demonstrate what I mean by that, let me just go ahead and start by drawing out an example nucleotide here for our purposes. Let's use deoxyribose. All right. So here recall that our nitrogenous base is connecting to the one prime carbon of our sugar backbone and our phosphate group is connecting to the five prime carbon. Now, on the three prime carbon. In the case of both deoxy rivals and rivals, we have a hydroxy group. So here when it comes to linking two nucleotides together, the three prime hydroxy group of the prior nucleotide is connecting to the five prime phosphate group of the following nucleotide. So on this example, nucleotide, I would for example, erase the hydrogen of the three prime hydroxy group and instead connect that oxygen to the phosphorus of the next nucleotides phosphate group. And so from there, I would go ahead and draw the deoxy rival sugar of the next nucleotide and so on. And so from here, we get a sense of the type of linkage that's necessary to hold these two together. And so when you consider this phosphate group of the second nucleotide, we have one phosphorus that's connecting the two oxygens that are both connecting to a carbon atom. And so that's what we call a phospho die a sur bant. The reason we say die ester is because once again, two oxygens connecting to phosphorus are connecting themselves to carbon atoms. So here this is ultimately going to be a phospho Doster bond, which means option C is our correct answer. A glyco cytic bond. If you recall is between monosaccharide units, hydrogen bonds are actually intermolecular forces and not covalent bonds. While peptide bonds for D connect two amino acids, not nucleotides. So there you have it. And with that being said, thank you. So very much for watching and I hope you found this helpful.

What nucleic acid subunits are connected in a phosphodiester linkage in a polynucleotide?

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Key Concepts

Nucleic Acid Structure

Phosphodiester Linkage

Polynucleotide Formation