Pearson+ LogoPearson+ Logo
Start typing, then use the up and down arrows to select an option from the list.

Cell Biology

Learn the toughest concepts covered in Cell Biology with step-by-step video tutorials and practice problems by world-class tutors

15. Cytoskeleton and Cell Movement

Actin Based Movement



Cell Crawling

Play a video:
Was this helpful?
Hi in this video we're gonna be talking about acting based non muscle movements. So this video is just going to focus on movements that are non muscle but that acting plays a huge role in. So there's three I want to mention there's one we're really going to talk about. The first is cell crawling. So this is kind of what we imagine when we imagine an entire cell moving right? You see maybe seen videos of amoebas, but essentially the cell is just dragging itself across the surface for some reason then and this is the one we're going to talk about most. Then you have chemo taxes and this is going to be a cell responding in some way. So it's got to be moving, remember this? There are movements so it's moving in some way in response to different chemical concentrations something that's entered its environment. So if it gets more calcium or more acid or something and it kind of chemical comes into its environ, then the cell will respond by moving chemo taxes. And then we have this really cool thing that I really actually like, I wish we were talking about it more. But this is cytoplasmic streaming and so this is where the outside of the cell is really staying stationary. But inside the cell you can see these like almost like waves these oceans of side us all sort of moving back and forth and more like I guess they're more like streams or rivers, like fast moving streams and rivers through a cell with a side of salt will actually move back and forth in the cell. And you can see them some in plant cells and slime mold. So, if you ever look at a plant cell under a microscope which you may in your labs, um you can actually see this under like microscope if you kind of know what you're looking for, but we're not actually gonna talk about that one that much. Instead, we're gonna focus on cell crawling. And so um cell crawling uses four steps to move across the surface. So the first step is the protrusion step, which means that the cell has these acting based protrusions that it extends out of its surface. And these protrusions are made up of acting. And so as they sort of grow and protrude out of themselves, that's going to be acting, growing and protruding out the plasma membrane. So what we call these protrusions differs depend on the cell type in things. So the one you're probably most familiar with or may have heard of before is Sudha podia. That's going to be the protrusions, you find an amoeba, but there are other ones, Lamela podia. And um this is gonna be a leading portion of the cell. And actually there's the actual protrusion, it's called the phillipe DEA at the leading edge and those are found in other organisms. But if you see any of these names in your books, you know that this is what it's talking about. This protrusion step, then we have this protrusion, it's out there, it's it's stuck itself out, but then it has to attach to the surface, whatever surface is on whether it's on a tissue or whether it's on plastic or you know, no matter where it's on slime, wherever it is, it's got to attach to that surface and how it does this is it attaches through proteins called inta grants. And integrates are actually on the sell their trans membrane proteins are going to be on the plasma membrane on the cell surface. And they attached their what attached to either the extra cellular matrix or the surface where the cell is crawling. So integrates are found on these protrusions and that's what allows them to stick and attach there. So you can kind of think of immigrants like velcro right? So if you attach them to a surface, that velcro is going to stick to the surface. And so that's what the inter grants do, then you have translocation. And so this is where the cell dragging part comes in. So now you have the front part of the cell like reaching out. It's now velcroed itself down through its integrations but it's behind, it's still like way back there. So then it starts to drag the rest of its body up and that's called translocation. Um and it uses those like velcro those integration bindings to like help itself pull, right? Because if it wasn't attached, it might just like shrink back to where it was before. But because it's attached here at these proteins, it's not going anywhere, it's going to anchor itself there so the rest of it's just gonna be dragged forward instead of the opposite thing occurring. And then you have finally detachment. So once the but gets up there to the front then um that velcro or these instagrams have said ok I've done my job so then they release and start the process over. So these are what these patrician looks like. These are from Amoebas, you can see these, they can kind of look like scary things but essentially they can go from really any surface um and extend forward um and help pull the cell along so that is a cell crawling I think. Yeah, that's it. So now let's move on.

Pseudopodia are used by ameobas for cell crawling.


Which of the following proteins are used so that the cell can attach to the surface on which it is crawling?