Transport Proteins of Facilitated Diffusion

by Jason Amores Sumpter
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So now that we know from our last lesson video that facilitated diffusion requires transport proteins in this video, we're going to talk about some of the transport proteins of facilitated diffusion. And really, there are two main types of transport proteins involved in facilitated diffusion, and we have those two number down below number one and number two. And so the first type of transport protein involved in facilitated diffusion are the poor ins otherwise known as channels. And so, as their name implies, porn's and channels, they're going to form an obvious, membrane spanning tunnel that will allow molecules to move across the membrane, Uh, by traveling through the tunnel that these parents or channels create. And so poor ins, uh, implies the word poor and poor is like a whole or like a tunnel, and channels once again are basically like tunnels as well. Now, aqua por ins are specifically used to transport water molecules across or through the cell membrane, essentially facilitating Oz moses so that as Moses, the diffusion of water across a semi permeable membrane can occur at a faster rate. Thanks to the aqua porn's now the second type of transport protein involved in facilitated diffusion are the transporters otherwise known as carriers. Now the transporters or carriers. Unlike the porn's and channels, they do not form an obvious membrane spanning tunnel. Instead, the transporters air carriers there, Onley open on one side of the membrane at a time, and they must undergo confirmation. All changes in order to move molecules across the membrane. So let's take a look at our image down below to get a better understanding of these ideas. So notice on the left hand side over here, what we're showing you are poor ins and channels. And so notice that porn's and channels they're going to create a membrane spanning tunnel that is basically going to allow molecules to move through the membrane through the tunnel and cross to the other side. Now, Aqua Porn's are specifically porn's that allow water molecules to diffuse across the membrane at faster rates, essentially allowing osmosis to occur faster. And you can see that channels like ion channels like this can allow ions that have charges like a positive charge, for example, to move through the tunnel here and get to the other side of the membrane. And so over here, what we see is that there are obvious membrane spanning tunnels, and so there's an opening on both sides of the membrane. Now, when we take a look at the right hand side of the image over here, notice that we're showing you transporters or carrier proteins. And so when you look at these, notice that it does not form an obvious membrane spanning tunnel like these do over here. Instead, the transporters are Onley open till one side of the membrane at a time. And so, in order to transport these molecules from one side of the membrane to the other side of the membrane, this transporter or carrier protein must undergo a confirmation. Allchin change. And so notice that over here the transporter carrier has undergone a confirmation. I'll change that can allow the molecule on the inside to be released to the other side of the membrane. And so what you'll notice is that here theme, the, um, transporter or carry your protein is only open till one side of the membrane, which is over here, and it's closed on this side of the membrane. And so transporters or carriers are Onley gonna be open toe one side of the membrane at a time. And it's on Lee after the confirmation of change occurs where they can change their shape and be open on the other side of the membrane. And so both of these are types of transport proteins involved in facilitated diffusion, allowing molecules to be transported down their concentration. Grady INTs passively, without any energy input. And so this here concludes our lesson on this, and we'll be able to get some practice applying these concepts as we move forward in our course, so I'll see you all in our next video.