- Nucleic acids are commonly taught in biochemistry courses and include DNA and RNA
- DNA is double-stranded and forms an alpha helix, while RNA is single-stranded
- DNA is mostly located in the nucleus and stores genetic information, while RNA can transfer genetic information and synthesize protein
- Both DNA and RNA are polymers made up of nucleotides, which consist of a sugar, nitrogenous base, and phosphate group
- DNA has deoxyribose sugar, while RNA has ribose sugar
- DNA bases include adenine, guanine, cytosine, and thymine, while RNA replaces thymine with uracil
- Purines (adenine and guanine) have two rings, while pyrimidines (cytosine, thymine, and uracil) have one ring
- Purines are attached to the ribose sugar at position 9, while pyrimidines have a different attachment point
- Adenine and guanine have slight structural differences, with guanine having an additional carbonyl group
- Thymine, uracil, and cytosine have similar structures with a six-membered ring and nitrogen atoms.

- The nitrogenous bases in DNA and RNA have a similar structure.
- The numbering of the atoms in the bases is important for understanding their structure.
- Thymine has a methyl group, while uracil and cytosine have a hydrogen in its place.
- Cytosine also has an NH2 group on carbon 4 and a double bond between positions 3 and 4.
- Uracil is found only in RNA, thymine is found only in DNA, and cytosine is found in both.
- A nucleotide has a sugar, a nitrogenous base, and a phosphate group, while a nucleoside only has a sugar and a nitrogenous base.
- The names of nucleotides and nucleosides differ based on the type of sugar and the presence of certain groups on the bases.
- Guanine is a purine base and when combined with ribose sugar, it becomes guanosine.
- Adding a methyl group to carbon 8 or removing a hydroxyl group changes the name of the nucleoside.

- The video explains how to name nucleosides and nucleotides
- Nucleosides are named based on the nitrogenous base and sugar they contain
- Nucleotides are named based on the nucleoside, sugar, and phosphate group they contain
- The position of the phosphate group is specified in the name
- Adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) are common examples of nucleotides
- The video also discusses the pairing of nitrogenous bases in DNA and the hydrogen bonds that hold the strands together

- The video suggests searching for a review on intermolecular forces and dipolar reactions on YouTube.
- The sugar phosphate backbone is on the left and right sides.
- The phosphate group is attached to carbon 3 and carbon 5 of the sugar units, forming a 3-5 phosphodiester linkage.
- The two strands of DNA are anti-parallel to each other.
- A pairs with T and C pairs with G in the complementary strand of DNA.
- The video concludes by encouraging viewers to subscribe and click the notification bell for future videos.

- Nucleic acids include DNA and RNA, with DNA being double-stranded and RNA being single-stranded
- DNA stores genetic information in the nucleus, while RNA transfers genetic information and synthesizes protein
- Both DNA and RNA are made up of nucleotides, consisting of a sugar, nitrogenous base, and phosphate group
- DNA has deoxyribose sugar, while RNA has ribose sugar
- DNA bases include adenine, guanine, cytosine, and thymine, while RNA replaces thymine with uracil
- Purines (adenine and guanine) have two rings, while pyrimidines (cytosine, thymine, and uracil) have one ring
- Nucleotides have a sugar, nitrogenous base, and phosphate group, while nucleosides only have a sugar and nitrogenous base
- Nucleosides and nucleotides are named based on the type of sugar, presence of certain groups on the bases, and position of the phosphate group
- DNA strands are held together by hydrogen bonds, with A pairing with T and C pairing with G
- The sugar phosphate backbone forms a 3-5 phosphodiester linkage and the two DNA strands are anti-parallel
- The video concludes by encouraging viewers to subscribe and click the notification bell.

This Biochemistry video tutorial provides a basic introduction into nucleic acids such as DNA and RNA.  DNA stands for deoxyribonucleic acid and RNA stands for ribonucleic acid.  Nucleic acids are composed of nucleotides which are made up of a phosphate group, a pentose sugar, and a nitrogenous base.  

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Here is a list of topics
1.  Intro to Nucleic Acids
2.  DNA and RNA
3.  DNA Structure - Double Stranded Alpha Helix
4.  RNA Structure - Single Stranded Nucleic Acid
5.  Basic Parts of a Nucleotide
6.  Nitrogenous Bases - Adenine, Guanine, Thymine, Cytosine & Uracil
7.  Purine and Pyrimidine Rings
8.  Nomenclature of Nucleosides and Nucleotides
9.  AMP, ADP, & ATP
10.  Basic DNA Structure
11.  DNA Strands Held By Hydrogen Bonds
12.  The Sugar Phosphate Backbone Structure of DNA
13.  How To Write The Sequence of the Complementary Strand of DNA

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1 of the topics that are commonly taught in a biochemistry course are nucleic acids.

Now you might be wondering what exactly are nucleic acids?

But both of these are different types of nucleic acids.

As you can see DNA is a double-stranded nucleic acid.

Now, DNA is mostly located in the nucleus, particularly in eukaryotes, whereas RNA, you can find it outside of the nucleus.

And DNA, basically, its function is to store genetic information.

Whereas RNA, it can be used to transfer genetic information from 1 part of the cell to another, and it can also be used to synthesize protein.

You have ribosomal RNA, transfer RNA, and messenger RNA.

Now you might be wondering what exactly is a polymer?

A polymer is basically a long molecule made up of tiny units called monomers.

And the monomers that make up DNA and RNA are known as nucleotides.

Now there's different types of nucleotides, but they all have 3 basic parts to it.

So each nucleotide has a pentose sugar, a five-carbon sugar,

So P stands for phosphate, S is for sugar, B is for base.

Now in DNA, the type of sugar that we have is a 5 carbon sugar known as deoxyribose.

Now I'm going to compare it to RNA so you can see the difference.

RNA has a ribose sugar instead of a deoxyribose sugar.

It still has a nitrogenous base and it has a phosphate group.

But the difference is an extra hydroxyl group.

Now let's go ahead and number the carbons on the ribosugar.

This is carbon 1, that's where the nitrogenous base is attached to.

Carbon 2, 3, 4, And carbon 5 is outside of the pentose ring.

And that's where the phosphate group is attached to.

So in DNA, notice that we don't have a hydroxyl group on carbon 2.

And so that is why it's called deoxyribose.

It's a deoxyribose sugar because it's lacking in oxygen.

That's why RNA is called ribonucleic acid.

But besides that, they both have a phosphate group and a nitrogenous base.

Now let's focus on the nitrogenous bases found in DNA and in RNA.

So DNA contains the bases adenine, guanine, cytosine, and thymine.

In RNA, the bases are adenine, guanine, cytosine,

So that's another difference between RNA and DNA.

It's a typical test question, so make sure you're aware of that difference.

So uracil is found in RNA, and thymine is found in DNA.

Now the nitrogenous bases that we've been talking about can be divided into these 2 categories, purines and pyrimidines.

1 of the ring is basically a six-membered ring and the other 1 is a five-membered ring.

Pyrimidines on the other hand contain only 1 ring and it's a six-membered ring.

Now the purines that you need to be aware of are adenine and guanine.

The pyrimidines include cytosine, thymine, and uracil.

Now let's talk about drawing these structures and also how to number them.

For some of you, you may need to be able to draw these structures on your tests.

And for those of you who don't need to memorize it, you can fast forward this section, or you can sit back, relax, grab a bag of popcorn, and just enjoy the show.

On the left side I'm going to draw adenine

and on the right side I'm going to draw guanine.

Now in the first ring They both contain 2 nitrogen atoms and 4 carbon atoms In the second ring they also contain 2

nitrogen atoms So both adenine and guanine have that same structure.

So if you start with the base structure, it can help you to remember how to draw these 2 purines.

Now both adenine and guanine, they have a double bond in the middle and they have another double bond in this position and here as well.

Now let's talk about where they're different.

If you don't see a hydrogen, that means that there's a lone pair on the nitrogen.

Now adenine has an NH2 group on this position right here so that's where it's different relative to guanine.

Guanine has an NH2 group towards the right and at the same time it has a carbonyl group in this location.

So if you remember that, it can help you to draw these 2 structures.

So that's the difference between adenine and guanine.

Now let's talk about numbering the rings.

So this nitrogen represents number 1, and then you need to count it in a counterclockwise direction.

Then you move on to the five-member ring.

We're gonna count it in a clockwise direction.

Now, what you need to know with purines is that when you attach them to a ribose they will be connected let me draw a ribose ring I'm just going to draw a box to represent a ribose, just to keep it simple.

But what I want you to take from this is that The ribose ring is attached to the nitrogenous base at position 9 when dealing with purines.

For pyrimidines it's different, but for purines, the ribose is attached to the N9 position.

So it's the 9th position on a nitrogen atom on a purine ring so you may need to know that for a test maybe not it depends on if your teacher is going to quiz you on that fact I don't know Now let's move on to the pyrimidines.

So there's 3 structures that we need to draw.

So once again, we're going to have a 6-membered ring with 2 nitrogen atoms and 4 carbon atoms, just like we had in the case of the purines.

We only have a 6-membered ring here, but we're not going

to have the 5-membered ring for the pyrimidines.

But the structure of the 6-membered ring is very similar.

So on the left I'm going to draw, let's start with thymine.

So all 3 of these nitrogenous bases, they have the same general structure.

The 6-membered ring, as you can see, it's very similar.

Now let's talk about the way we're going to count it.

to be number 1 and we're going to count it in a clockwise direction.

Now the ribose will be attached to the nitrogenous base at the N1 position.

So make sure you keep that in mind if you're taking notes.

Now I'm going to get rid of the numbers but you can add it there in your notes.

So this is going to be a hydrogen in the case of thymine and we're going to have a double bond between positions 5 and 6.

And the same is true for the rest of them.

Now for thymine, we have a carbonyl group at position 4 and another carbonyl group at carbon 2.

Now, uracil looks very similar to thymine with 1 key difference.

Thymine has a methyl group, but uracil does not.

And so that's the difference between thymine and uracil.

If you don't see it, it's an invisible hydrogen, but it's there.

Now in the case of cytosine, we have a carbonyl group on carbon 2 just like thiamine and uracil so they're similar in that respect.

However, we do have something different in cytosine and that is we have an NH2 group on carbon 4.

And so that's how cytosine differs from thymine and uracil.

In addition to that, it also has a double bond between positions 3 and 4.

So those are the 3 pyrimidines that you may need to know.

And just remember, uracil is found only in RNA, thymine is found only in DNA, and cytosine is found in both DNA and RNA.

What is the difference between a nucleotide and a nucleoside?

Perhaps you've heard of the word nucleoside.

As mentioned before, it has a ribose or a deoxyribose sugar, it has a nitrogenous base which could be a pyrimidine with 1 ring or a purine with 2 rings, and it also has a phosphate group.

Now, in the case of A nucleoside, it doesn't have 3 parts.

It has the 5-carbon sugar and it has the nitrogenous base.

But once you add the phosphate group to a nucleoside, then it becomes a nucleotide.

So make sure you understand the difference and also the naming.

So let's say this is cytosine, which is 1 of the 3 pyrimidines we talked about.

When you add the ribose sugar to it, it becomes a nucleoside and it's called cytidine in the case of RNA.

But in the case of DNA, it's deoxycytidine.

And it really depends on the presence of the 0 group on carbon 2.

There's always going to be an 0 group in carbon 3, but if we don't have an 0 group in carbon 2, it's called deoxycitidine.

If we do have it, then it's called citidine.

If the nitrogenous base is called cytosine and if the nucleoside is called cytidine, what is the name of the nucleotide that contains the cytosine nitrogenous base?

So it's going to sound weird but it's called

Chances are you probably don't need to know that for your test, but for those of you who may need to know it, that's what the nucleotide is called.

So when you hear the word cytosine, it's not referring to this entire nucleotide, but rather just the base that's in the nucleotide.

But if you hear acetyl-dilate, that's the entire nucleotide.

So here is a summary that can help you with the nomenclature of nucleosides and nucleotides.

On the left, we have the nitrogenous base adenine.

Once we add a ribosugar to it, it becomes adenosine.

And then if we add the phosphate group, it becomes adenine, excuse me, wow, I said that wrong, adenylate.

Looking at guanine, the situation is similar.

As a nucleoside it's guanosine and as a nucleotide with a phosphate group, guanylate.

Now the nitrogenous base thymine, once we add a ribosugar to it, it becomes thymidine or thymidine, if that's how you say it.

But since thymine is found in DNA, chances are it's going to be added to a deoxyribose sugar, and so it becomes deoxythymidine.

And instead of thymidylate, it becomes deoxythymidylate in DNA.

My pronunciation of these names may not be the best so Don't quote me on that.

You can look it up yourself But these are the names that corresponds to the nitrogenous base to nucleosides and the nucleotides

Now let's talk about naming nucleosides, How would you name this particular nucleoside?

need to do is identify the type of nitrogenous base that we have.

Now based on the structures that we drew earlier, what kind of base do we have?

Well, first, is it a purine or is it a pyrimidine?

Now, if you recall, pyrimidines are nitrogenous bases that have only 1 ring.

So because this is a 2 ring nitrogenous base, we have a purine.

Now there's 2 purines you need to be familiar with, and that's adenine and guanine.

So this particular nitrogenous base is called guanine.

Now what does it become once we add a sugar to it?

Guanine plus the ribose sugar becomes the nucleoside guanosine.

This is position 1, 2, 3, 4, 5, 6, 7, 8, 9.

So as we can see, the purine is attached to the ribose at the knife position on the nitrogen atom.

Now what happens to the name If we put, let's say, a methyl group on carbon 8, how do we name this particular nucleoside?

Let's say if we replace this with a hydrogen,

So now we have a deoxyribose and so this is going to become deoxyguanosine.

So now, the way we're going to name it, I'm running out of space here, so let's see if I can fit it in.

It's going to be 8-methyl-2-deoxyguanosine.

Because we don't have the oxygen or the hydroxyl group rather on carbon 2 of the ribose sugar.

And so that's a simple example of how you can name a nucleoside with a purine ring.

So how can we name this particular nucleoside?

So first, let's start with the nitrogenous base.

Now, we have a 1 ring nitrogenous base, so that means it's a pyrimidine, and we have 3 options.

It's either cytosine, thymine, or uracil.

Now, looking at the NH2 at the top, only 1 of those 3 pyrimidines have the NH2 on the top.

And if you remember, this is the nitrogenous base cytosine.

Now combined with the ribose sugar it becomes a nucleoside called cytidine and so that's the name of this particular nucleoside.

Now how will the name change if we add a methyl group to that carbon?

And also, remember that the ribose is attached to the pyrimidine ring at the N1 position.

Now let's shift our focus to naming nucleotides.

So how can we name this particular nucleotide?

So the nitrogenous base that we have, this is G, and so that's guanine.

When we combine it with the sugar, it becomes a nucleoside called guanosine.

But now, how do we name it once we have the phosphate group?

guanylate when the phosphate group is at position 5.

Another way in which we can name this particular nucleotide is we can start with the name of the nucleoside, guanosine, and then specify the location of the phosphate.

So We could say guanosine-5-monophosphate because we have 1 phosphate attached to the ribose sugar.

And so that's how we can name this particular nucleotide.

So this time, the nitrogenous base that we're going to use is adenine.

And the phosphate group is going to be placed in a different position.

So you can also see phosphate represented this way.

So given the base adenine, Once we combine it with the sugar it becomes the nucleoside adenosine.

Now the phosphate group is located on carbon 3 of the ribose ring.

So to put it together we're going to start with the name of the nucleoside Adenosine and then specify the location of the phosphate group so adenosine dash 3 dash mono phosphate

And so that's how we can name that particular nucleotide.

So we're going to use the same nitrogenous base adenosine.

But this time we're going to have multiple phosphate groups.

So let's say if we have 3 of them, How do we name it now?

So we're going to start by naming the nucleoside.

So if we combine the ribosugar and the nitrogenous base, that is called adenosine.

Now we have 3 phosphate groups and so it's going to be called triphosphate, triphosphate, and it's located on carbon 5.

Now, this particular nucleotide has a common name, and so sometimes the 5 is just ignored because it's a very common molecule.

And so it's simply referred to as adenosine triphosphate.

And perhaps you heard of it as this molecule, ATP.

For instance, if you hear the word ADP, it stands for adenosine diphosphate.

So instead of having just 1 phosphate group or 3, now you have 2 phosphate groups.

And if you hear the abbreviation AMP, this is adenosine monophosphate.

So there's just 1 phosphate group instead of 2 or 3.

So what I'm going to do at this point is draw a representation of a DNA strand.

So here we have our sugar attached to a phosphate group

and then this is going to be attached to a nitrogenous base.

So let's put cytosine in it and over here it's going to be attached to another phosphate group and then that's going to be attached to another ribose sugar, actually deoxyribose since we're dealing with DNA.

And so this is going to be adenine this time.

This time, and then we're going to have another phosphate group.

Now at this point, go ahead and draw the complementary strand on the right side, using the left side as a starting point.

So first let's draw the nitrogenous bases that will pair up with C, A, and C.

And then attached to each nitrogenous base, we have the sugar, but notice the direction of the sugar, how it's like pointed up.

For the complementary strand, it's gonna be pointed down.

And then we're going to have a phosphate group attached to it.

And here we have another phosphate group and then another sugar unit.

We're going to talk about the connectivity of the phosphate group shortly.

Now what you need to know is that C, cytosine, will always pair up with G, guanine.

Adenine, A, will always pair up with thymine in DNA and T will pair up with A.

Now the next thing you need to put are the hydrogen bonds located between these base pairs and so it's the hydrogen bonds that keep the 2 strands in DNA attached to each other.

So there's 3 hydrogen bonds connecting C and G.

Now between A and T, there are 2 hydrogen bonds holding them together.

Now if you recall from chemistry, hydrogen bonds exist whenever hydrogen is attached to elements such as oxygen, nitrogen, or fluorine.

And an H bond is basically an intermolecular force that exists between separate molecules.

Now for those of you who may want to review on that, if you do a YouTube search, type in intermolecular forces organic chemistry tutor, you should see a video that will give you a review on intermolecular forces and dipolar reactions and things like that.

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Nucleic Acids - RNA and DNA Structure - Biochemistry