Primary Structure of Nucleic Acids - Video Tutorials & Practice Problems
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Primary Structure of Nucleic Acids Concept 1
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Hey, everyone. So we're going to say here that the primary structure of a nucleic acid is the sequence of n nucleotides attached through phospho bonds. Now, remember we said that a nucleotide is made up of three important parts. We have our phosphate group, we have our penthos ring and then we have our nitrogenous space. Two of these nucleotides can be connected to each other through phospho bonds. When we talk about the primary structure, it's just a chain of these nucleotides connected with multiple phospho disaster bonds. Now, here, the phospho disaster bonds themselves. Well, these are the bonds of the phosphate group that connects two sugars in the primary structure. If we take a look here, we see a phosphate group here and it's connecting this sugar and this sugar. So that's why we have these purple bonds. Here's this phosphate group here we have this purple bond and this purple bond because it connects these two sugars. We're gonna say the repeating phosphate sugar phosphate sequence forms the N nucleic acid backbone. So we have our backbone here in the darker blue. And remember coming off of the sugar itself is our nitrogenous base. These nitrogenous bases could be the same or they could be different. So you will say this is nitrogenous base 12 and three. So just remember that two nucleotides can be connected to one another through a phospho bond. When we have a string of nucleotides connected by multiple phospho dias bonds, this becomes the primary structure of our nucleic acid.
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Primary Structure of Nucleic Acids Example 1
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Here, we're told that a pin nucleotide has a base sequence of gauc A based on the given sequence, what is its likely origin? So where does this sequence originate from? And we can figure this out based on this sequence. So these are our nitrogenous bases because they're nitrogenous bases that will rule out fructose, which is a carbohydrate and OIC acid because it's a fatty acid because these are nitrogenous spaces. That means that's gonna be either DNA or RN A. Now, what's the key differences between them? Remember, the key difference is that DNA uses thymine as one of its nitrogenous spaces abbreviated T and RN A uses ell, abbreviated you. Since there is a Euro cell involved within the sequence, it would have to be RN A. That's being discussed here. So here our final answer would be option C. This represents RN A as the origin for this nucleotide or base sequence.
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Primary Structure of Nucleic Acids Concept 2
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So now remember that the primary structure of a nucleic acid is the sequence of nucleotides connected through phospho disaster bonds. With this idea, we have a new term directionality. Now this is the sequence of nucleotides being read and it's read from the five prime end to the three prime end. A good way to remember which end is, which is our memory tool, which is phosphate. Foss sounds like the letter F equals five. So here we're going to say that this is uh two nucleotides connected by a phospho dia bond. If we imagine it just being elongated further by more nucleotides and more phospho dier bonds, we'd say at this end where we have our free phosphate group phosphate equals five. This would be our five prime end. And if that's the five prime end, then down here where we have this free oh group that represents our three prime end. And again, we're reading it from five prime to three prime. So looking at this error, we're going from five prime to three prime. This is how we interpret the primary structure of nucleic acids. If we're reading the chain of nitrogenous spaces involved, because here, the nitrogenous spaces is where we can get differentiation in terms of our different primary structures of nucleic acids, different orders of our nitrogenous bases. In turn over time can lead to different types of proteins being created from this primary structure, right? So just keep that in mind, phosphate equals five. The free phosphate end is the five prime end. The free oh end is the three prime end.
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Primary Structure of Nucleic Acids Example 2
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In this example question, it says which of the following statements about primary nucleic acid structure is incorrect. A the structure and function of a nucleic acid is based on the sequence of the connected nucleotides that there is true. The sequence of nitrogen in spaces is read from the five prime to the three prime end. This is directionality. So this statement is also true. Uh phospho disaster bond represents a bond between the phosphate group and the sugar. That is also true. So here the last one, the difference between nucleic acid is the result in the difference of the sugar attached to the backbone. So remember the diversity or differences between our nucleic acids is really based on the differences in their nitrogenous bases, not the backbone. So this statement D is a statement that is incorrect out of all the options given.
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Problem
Problem
Draw the full structure of the DNA trinucleotide G-A-T and label its 5’ and 3’ ends.
A
B
C
D
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Problem
Problem
Draw the following primary structure based on the following description:
Draw 3 nucleotides with deoxyribose sugars with dTMP bases connected by phosphodiester bonds.
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