In this video, we're going to introduce electron carriers, specifically NADH and FADH2. It's important to note that many biological processes that we're going to talk about moving forward in our course, including cellular respiration, conduct redox reactions using electron carriers. These electron carriers are helpful to perform redox reactions. Electron carriers such as NADH and FADH2 are each going to carry or transport a maximum of 2 electrons. These NADH and FADH2 electron carriers can shuttle electrons to different locations within a cell, kind of like an electron taxi cab.
You can think of NADH and FADH2 as electron taxi cabs, and we'll be able to see that down below in our image. It's also important to note that NAD+ and FAD are the oxidized forms of NADH and FADH2 respectively. Recall that in oxidation, symbolized by "Leo," the lion goes "ger," and "Leo" represents oxidation. This means that NAD+ and FAD are both going to have fewer electrons. They're going to have lost electrons in comparison to NADH and FADH2.
Let's take a look at our image down below to clear some of this up. These electron carriers that we're going to be talking about, NADH and FADH2, really act like electron taxicabs. Notice here in this image, we're showing you an electron taxicab. On the left-hand side, notice that we have the empty form of the electron taxicab. But of course, when this electron taxicab picks up its 2 passengers, these 2 electrons, it's going to become a full taxicab.
Over here we have the 2 electrons inside of this electron taxicab. NADH will form when the oxidized form, the NAD+, the empty taxi cab version, picks up its 2 passengers, these 2 electrons along with a hydrogen ion, and it forms NADH. You can see that NADH is carrying these 2 electrons, but it also picks up a hydrogen atom as well. When we look at FAD, this is the empty taxicab version of FAD, this electron carrier, but when it picks up its 2 passengers, these 2 electrons, it also picks up 2 hydrogen ions as well and it becomes FADH2, the full taxicab version of this electron carrier.
One way to help you guys remember, a helpful memory tool to remember that NADH and FADH2 are the full taxicab versions, is to just think that NADH and FADH2 are just a little bit heavier because they're gaining electrons and hydrogens. The ones that have "h" in them are going to be a little bit heavier, and these are the full taxicab versions. What you'll learn as we move forward in our course talking about cellular respiration is that during cellular respiration, these electrons carried by NADH and FADH2 are going to go to what's known as the electron transport chain, which is the final stage of cellular respiration. We'll talk more about this as we move forward in our course.
But for now, you can see that this full electron taxicab here, notice one of the electrons is asking, "Where are we going?" and the other electron is responding, "To the electron transport chain, duh." Remember moving forward in our course we're going to learn that these NADH's and FADH2's are going to take their electrons to the electron transport chain during cellular respiration. This concludes our brief introduction to electron carriers NADH and FADH2, and we'll be able to get some practice applying the concepts that we've learned here as we move forward in our course. So I'll see you all in our next video.