This video, we're going to differentiate between enveloped and non-enveloped viruses. Recall from some of our previous lesson videos that some viruses have a lipid bilayer on the outside of their structure. This lipid bilayer that some viruses have is called an envelope. Enveloped viruses are going to be viruses that have an outer lipid bilayer. This outer lipid bilayer, or this envelope that these envelope viruses have, is usually obtained from the host cell that they infect, usually as they exit the host cell. A matrix protein links the lipid bilayer or the envelope to the remaining nucleocapsid of the virus. These enveloped viruses actually tend to be more susceptible to soaps and detergents. That's because soaps and detergents are capable of damaging that lipid bilayer or damaging that envelope. So, soaps and detergents can be really effective at making these enveloped viruses noninfectious. It turns out that the COVID-19 virus that caused the COVID-19 pandemic is actually an enveloped virus, which is why washing your hands with soap can be so effective at limiting the spread of that disease.
Non-enveloped viruses, on the other hand, are sometimes referred to as naked viruses. These non-enveloped viruses, or naked viruses, do not have an outer lipid bilayer. They do not have an envelope. They only consist of a nucleocapsid.
If we take a look at our image down below, we can get a better understanding of envelope viruses and non-envelope viruses. Notice on the right, we're showing you an enveloped virus, which can be symbolically represented as a letter inside of an envelope. On the right-hand side over here, we're showing you a non-enveloped virus, which can be symbolically represented as just a letter without the envelope. Focusing on the enveloped virus first, on the left-hand side, again, the virus that causes COVID-19, which is called SARS-CoV-2, is right here, and it is an example of an enveloped virus. It has an outer lipid bilayer, referred to as the envelope. The lipid envelope is linked to the nucleocapsid by these specific pink proteins that you see throughout here. These pink proteins are the matrix proteins. That's exactly what we discussed above. These proteins link the lipid envelope to the nucleocapsid. You'll also notice that in addition to having the envelope, embedded in the envelope are the spike proteins that the enveloped viruses use to bind to the surface receptors of the host cell to initiate an infection. There may also be other surface proteins as well in that envelope. You can see over here in this image. You can see that this represents the envelope, and the spikes are pointing out of the lipid envelope.
On the right, again, we're showing you a non-envelope virus. They do not have a lipid bilayer. They do not have an envelope, and they only consist of a nucleocapsid. Again, this is the nucleic acid, either DNA or RNA, and the capsid is the protein shell. The spikes will be sticking out of the capsid for these non viruses. A classic example of a non-enveloped virus is this adenovirus that you see over here on the right.
This concludes our brief introduction to enveloped and non-enveloped viruses. We'll be able to get some practice applying these concepts and continue to learn more about viruses as we move forward in our course. So, I'll see you all in our next video.