In this video, we're going to begin our lesson on hydrogen bonding. A hydrogen bond is commonly abbreviated as just an H bond because the letter H is the chemical symbol for hydrogen. A hydrogen bond or an H bond is really just defined as an interaction between a highly electronegative atom such as either fluorine, oxygen, or nitrogen, and of course, a hydrogen atom itself. How could you have a hydrogen bond without a hydrogen atom? Every hydrogen bond is going to have a hydrogen atom involved. However, the highly electronegative atom will vary. Sometimes it will be fluorine, other times it will be oxygen, and other times it will be nitrogen. But what can help you remember the highly electronegative atoms that form hydrogen bonds is that hydrogen bonds are pretty fun, and so you can think FUN here sounds like fun, and so those are the 3 electronegative atoms that can help form hydrogen bonds. Notice down below in our image, we're showing you a few examples of hydrogen bonds, and we'll talk about them here shortly.
One thing to note about these hydrogen bonds is that individually the H bonds or the hydrogen bonds are really, really weak. However, collectively, if you have lots and lots of hydrogen bonds forming, they can be quite strong. These hydrogen bonds are important in several different areas of biology, including the properties found in water, which we'll get to talk more about later in our course in a different video. Hydrogen bonds are also important for the structure of macromolecules, which we'll get to talk more about later in our course as well. Notice in our image, we're showing you some examples of hydrogen bonds in biology. On the left, we're showing you how water molecules can form hydrogen bonds, and notice that we have these three different water molecules, H2O, and notice that through hydrogen bonding, they can actually form interactions between these different water molecules. This yellow bond right here represents the hydrogen bond and notice that it's forming between a hydrogen atom, as indicated above, and another highly electronegative atom, in this case, it's showing oxygen in the water molecules.
Now that is going to be very important. The hydrogen bonding in water is going to be very important for specific properties that water has that are really important for life. We'll talk about these properties of water later in our course in a different video. It's important to know that water does form hydrogen bonds.
On the right-hand side, we're showing you how nucleotides can also form hydrogen bonds. Here, we're showing you one nucleotide and over here another nucleotide, and notice that between these two nucleotides there are hydrogen bonds forming. Notice that this first hydrogen bond up here at the top is forming between a hydrogen atom and a highly electronegative oxygen atom, but this other hydrogen bond down below is forming between a hydrogen atom and another highly electronegative atom, a nitrogen atom. Remember that the highly electronegative atom can vary. It can either be fluorine, oxygen, or nitrogen, and here in this scenario, you can see that it's forming between nitrogen and hydrogen and oxygen and hydrogen. Don't worry too much about what nucleotides are right now. We'll talk more about nucleotides later in our course in a different video. For now, what you should know is that these nucleotides are going to be found in the structure of DNA. Later in our course when we talk more about DNA, we'll revisit this idea of how hydrogen bonds form between DNA structures.
But for now, this here concludes our introduction to hydrogen bonding, and we'll be able to get some practice applying these concepts in our next few videos. So, I'll see you all there.
