In this video, we're going to begin our overview of prokaryotic cell structures. Prokaryotic cells have a variety of structural components, both on the outside and the inside of the cell. Notice the table below that organizes all these prokaryotic cell structures based on their location, whether on the outside or inside of the cell. This table in our video is just an overview of these structures. As we move forward in our course, we will talk more about each of these individual structures in their own separate videos. Keep that in mind as we go through this table and fill it out, that this is just the very first introduction and a brief overview of what we're going to cover moving forward.
Starting here, we're focusing on the prokaryotic structures on the outside of the cell. The first structure we have is the cell walls, which are the outside layer that protects the cell from damage. In this image over here, the cell wall is represented by a blue background. Next, we have the plasma membrane, which we discussed in previous videos. The next structure is the glycocalyx, a sticky layer secreted by the cell to form biofilms. Biofilms are communities of microbes that live together and can stick to each other through the glycocalyx, which consists of polysaccharides and proteins. We'll discuss biofilms and the glycocalyx in more detail later in our course.
The next structure is the pili, long protein filaments that extend from the cell surface. Notice here we have our bacterial cell, and extending off our bacterial cell is this long protein filament that we call a pilus (or pili, for plural). The next structure is cilia, which are short protein filaments that are important for movement. We'll discuss more about them later in our course. Next, we have the flagella, which are also long protein filaments, but unlike pili, flagella are mainly used for cell movement.
Moving on to the inside of the cell, we have ribosomes, which are the site of protein synthesis, essentially the site of translation where protein synthesis occurs in the cytoplasm. Next, we have plasmids, circular double-stranded DNA molecules independent of the chromosome. Over here, you can see a bacterial cell; the bacterial chromosome is in red, but the plasmid, a separate circular piece of DNA separate from the bacterial chromosome, is shown in green. We'll discuss plasmids in more detail later in our course.
Then we have inclusions, molecular vesicles in the cytoplasm that contain important contents. We'll talk about different types of inclusions later in our course. Lastly, we'll also discuss endospores, dormant cell types resistant to damaging conditions such as heat, shown here on the right in the structure of an endospore.
This concludes our brief overview of the prokaryotic cell structures, which we'll discuss in more detail as we move forward in our course. I'll see you all in our next video where we can start to get some practice based on this overview.
