You are participating in a study group preparing for an upcoming ...

Question

You are participating in a study group preparing for an upcoming genetics exam, and one member of the group proposes that each of you draw the structure of two DNA nucleotides joined in a single strand. The figures are drawn and exchanged for correction. You receive the accompanying diagram to correct:

Draw this single-stranded segment correctly.

Accepted Answer

Hi, everybody. Welcome back. Let's look at our next question. It says two of the three phosphate groups removed from D N T P during the formation of the Phospho Dira bond are referred to as blink Choice A bi phosphate. Choice B di phosphate, choice C pyrophosphate or Choice D poly phosphate. So as you recall, when a nucleotide is added to the new DNA chain, It comes in as a nucleotide tri phosphate with three phosphate groups attached. And when the new phospho Dira bond is formed, two of the groups go off still bound together during that formation. And those two joined phosphate groups are referred to as and the answer is C pyro phosphate. We'll just look briefly at other answers. Uh Di phosphate interestingly is technically correct for that molecule. It's the oppa name. But our question says that these, this group of two phosphates is referred to as and pyrophosphate is the way it's generally referred to most often. That's what you'll see in your textbooks. So that's why I wouldn't pick Choice B Choice A bi phosphate also refers to two phosphate groups that uh prefix by but is usually used when you have two separate phosphate groups attached in different places on a molecule. So you'd say something like 12 B phosphate and these are two phosphate groups attached to each other. So choice A is not correct. And finally, choice D poly phosphate would refer to a polymer with multiple phosphate subunits. But we're not talking about a long polymer. Just those two that come off when that new phospho dier bond is formed in adding nucleotides to a DNA chain or an R N A chain. So choice D is not our answer either. So again, two of the three phosphate groups removed from AD N T P during the formation of the phospho dira bond are referred to as Choice C pyrophosphate. See you in the next video.

Key Concepts

Structure of DNA Nucleotides

Single-Stranded DNA

Phosphodiester Bond

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