Microscopes

in this video, we're going to introduce microscopes. And so a microscope, as its name implies, is really just an optical scope that is used to visualize micro skop ycl e small objects such as sells, for instance. And so the root micro is a route that means small and of course, scopes are going to be objects that we look through with our eyes. Now, really, there are two main types of microscopes that are commonly used that you all should know about, and we've got these two microscopes number down below number one and number two. And so the first type of microscope that you all should know is the light microscope, which, as its name implies, uses light to magnify small objects and make those small objects appear larger. Now the second type of microscope that you all should know is the electron microscope, which is much more complex, much more advanced and a much more powerful toll than the light microscope. And that's because electron microscopes, as their name implies, uses electrons for an even higher magnification of small objects. So let's take a look at our example down below at the ranges of the human eye light microscopes and electron microscopes. So when we take a look at this image, noticed that it has this scale here, with all of these numbers showing different units of length and so you can see here for perspective, the human falls over here on the right hand side and Adam's fall over here on the far left hand side. And so what that means is that the left hand side over here represents things that are really, really small. And then, of course, the right hand side over here represents things that air much, much larger or things that are large. And so that's important to keep in mind. And as we go from left to right, things are getting larger. And so what you'll notice here is at the bottom and green. We have the range of the human eye, and of course, we know that our eyes are able to visualize really, really large things. So it goes much, much beyond the scale of the size of humans. But in terms of small, there is a cut off, and so the range of the human eye can Onley see things that are so small and so If we want to be able to visualize things like most plant and animal cells and most bacteria and archaea, then we're going to need to utilize microscopes. And so notice that here we have and blew the range of the light microscope and the light microscope. What you can see is going to be used to visualize things such as most plant and animal cells as well as most bacteria and archaea. But ultimately, the light microscope also has a cut off, and it's not gonna be able to be powerful enough of a magnifying tool to visualize viruses for the most part. And so if we want to visualize things that are even smaller than we need to use another type of microscope, which we just defined as the electron microscope. And so the electron microscopes here notice are much, much more powerful tools, and they could be used to visualize most plant and animal cells. Most bacteria and archaea viruses, molecules such as proteins and lipids, uh, even smaller molecules such as water and Adams themselves. And so electron microscopes are very, very powerful and very expensive tools, whereas the light microscopes are microscopes that are still helpful for magnifying lots of small cells, but they're not nearly as powerful tools. They're not nearly as expensive. And so most of you, if you've taken a biology lab before, you may have even used a light microscope yourself before. In the past, however, the electron microscopes as well get to learn more about in our next video, are much more expensive. And, uh, the chances that you would have used an electron microscope are very, very slim just because of how expensive they are. And so you can see here that frog eggs are actually cells that we can actually visualize with our human eye. So some cells are we actually are able to visualize with our human I. But notice that most plant and animal cells and most bacteria and archaea are gonna fall outside of the range of the human eye. They're just too small for us to see on see. So here you can also see ants, which you might think of as being really, really small, but in perspective to things like Adams. Ants are incredibly large. That's why they're towards the larger side here now. One other major take away of this image is that most plant and animal cells, which we know from our previous lesson videos are eukaryotic cells are larger than most bacteria and archaea, which we know are smaller in our pro carry attic cells. And so that is another big take away of here. Most plant animal cells or most eukaryotic cells, are going to be significantly larger than most bacteria and archaea or most pro carry attic cells. And so this year concludes our introduction to microscopes, and we'll be able to talk a little bit more about electron microscopes in our next lesson video, so I'll see you all there.

So now that we know that electron microscopes are very powerful magnifying tools in this video, we're going to talk about some different types of electron microscopes. And so, really, there are two main types of electron microscopes that you all should know that are used to study both external and internal cell structures. And so we've got these two electron microscopes shown down below. The first is going to be the scanning electron microscope or the S E M for short. And so the scanning electron microscope, or the ECM is specifically used to visualize external cell surfaces and structures on the outside surface of cells. Now the second type of microscope that you all should know is the transmission electron microscope or the T E M for short. And so the transmission electron microscope or T. E. M. It's specifically used to visualize internal cell structures and organelles. So let's take a look at our image down below. Two. Better get a better understanding of this notice on the left hand side. Over here we have this really fancy piece of equipment, and this piece of equipment here is as scanning electron microscope. It's a very, very fancy and a very, very expensive microscope that's used to visualize external cell structures. And so you should know that ECM Zehr used to visualize external cell structures on the surface of cells and then over here on the right hand side of the image, we have another fancy piece of equipment and this fancy piece of equipment. Here is a transmission electron microscope or a T e m. Another incredibly expensive piece of equipment that's used to visualize as this image shows over here, internal structures and organelles within cells. And so moving forward, we're going to be talking about lots of different cell structures. And it's important to know that scientists can actually visualize these cell structures using either S. E. M's if it's external cell structures or t E. M's if they are internal cell structures. So this year concludes our introduction to the different types of electron microscopes, and we'll be able to get some practice applying these concepts in our next video. So I'll see you all there

What type of microscope would a researcher use to measure the size of a ribosome inside a eukaryotic cell?

• A. A magnifying glass.
• B. Standard light microscope.
• C. Transmission electron microscope.
• D. Scanning electron microscope.