Kinesins and Dyneins - Video Tutorials & Practice Problems

Kinesins and Dyneins

in this video, we're gonna be talking about connections and donations. So we all know that sales have to transport things throughout the cell because that's how they function and interact with different organelles in different cells. And so we're going to talk about transport specifically how they do this and which proteins they use. So there are two types of cellular movement. There is this thing called brownie and movement. And um this actually doesn't even have to be cellular. There's just two kinds of movement that we're going to talk about. The versus brownie and movement. These are random thermal motions. So the best way I can imagine this is if you have a glass of water and you just Sprinkle a little pepper in there and you actually just watch that pepper really closely, even if you're not holding the water, even if it's just sitting on a table, like not no one's moving it, there's not an earthquake. This water is still, you're going to see that pepper still move and it's going to move very slowly, but it's still going to move. And so that moves. Not because anything is pushing it, but because there's these just random thermal motions that cause it to float around essentially. But that's not the movement we're going to talk about the movement that we're focusing on is solitary movement. So this is jerky stepwise movement, but this movement has a purpose. These things are going somewhere and they have something to do. Um they're not just like pepper like randomly floating in a glass of water, there's, there's a function for this. Um, and usually they move in one single direction. So this type of movement in the cell is run by motor proteins. And so motor proteins what they are. They're proteins that use energy from A. T. P. To transport molecules across a microbial in a single direction. So they only go one direction. So the two classes of these are keynesians and dine ins. So keynesians move molecules towards the plus end of the microbial which is going to be away from the cell body. So away from the cell nucleus out out towards the plasma membrane. There are multiple kinds 14 families of these but Chinese and one is the one we're going to focus on as an example. It's the most prominent. Um and it's the one you need to know about. Then there's finance these new molecules the opposite way towards the minus end. So this is gonna be directing towards the cell body. And Damien's interact with these special proteins called dine acting proteins and they keep dining and attached and help Danny and move cargo molecules over long distances. Um So the cell is kind of big in relation to a single protein. And so those are kind of very far distances if you're traveling for the nucleus to the plasma membrane. So sometimes they need extra proteins to help them along, help carry. Help keep them motivated to keep going. And so dine acting proteins with that. Now there are multiple classes of motor proteins and each one has a different speed. Um Each one has you know goes different places and has different functions, carriages different things. Um So these kind of these large families. Um But I think it's interesting that they all have different speeds. So it's just kind of like I don't know different cars have different speeds and different motor proteins have different speeds as well. So here you have examples of what they look. They have this funny shape here which will actually get into in a second. But you can see dining options are moving towards the minus end whereas many sins are moving towards the plus end. So this is going to be towards the cell body and this is gonna be away from the cell body. So if we were to, you know draw a cell here, the nucleus would be this direction. Whereas the plasma membrane would be up here, that's what that would look like. So motor proteins, like I just said they have a specific structure. So you have these so their diners. First of all it means there's two subunits. Um And they have two heads and a single tail. So they look like this. And so the two heads bind to the micro tubules in one orientation meaning either the plus or the minus in. And they are responsible for hydra lies in the A. T. P. To A D. P. As they move along the micro tubules. The tail on the other side acts that's what binds to the cargo and carries it throughout the cell. And so the heads go through these repeated cycles of a teepee hydraulic sis to continually bind and step forward, bind and step forward and release. Um So they just kind of step forward. I'll show you an image that in a second and so it's called process it movement when this movement is occurring for really long distances but it's not falling off. And so motor proteins are like that. Motor proteins can carry things for throughout the entire style without falling off. So they're given a special process of movement term. So here's Kinison. Um so here's the micro tubules. Let me back out of the way. You can see everything. Here's the micro tutorial, you can see the different subunits, alpha beta two billon. And here you have the kindness in with its two heads and its tail. And you can see that it kind of just like wobbles down, you know. So here it's bound to a D. P. This is going to be bound to a T. P. And it switches between a T. P. And a. D. P. Um In order to project the kidneys and forward down the microchip real. So that's how many seasons dining and motor proteins work. So now let's move on

Kinesins move molecules away from the cell body

• A. True
• B. False

Where do motor proteins get the energy to move molecules throughout the cell?

• A. ATP
• B. GTP
• C. Breakdown of H₂O
• D. Breakdown of sugars

Which of the following motor protein structures directly attaches to the cargo to transport it throughout the cell?

• A. One globular head
• B. Both globular heads together
• C. The motor protein tail
• D. The microtubule