Note the spikes that adorn the outer surface of the virus, which impart the look of a corona surrounding the virion, when viewed electron microscopically. In this view, the protein particles E, S, and M, also located on the outer surface of the particle, have all been labeled as well. See PHIL for a black and white version of this image. The artistic recreation was based upon scanning electron microscopic SEM imagery. PHIL ID Download high-resolution image Description: This illustration provided a 3D graphic representation of a spherical-shaped, measles virus particle, that was studded with glycoprotein tubercles.
Those tubercular studs colorized maroon, are known as H-proteins hemagglutinin , while those colorized gray, represented what are referred to as F-proteins fusion.
The F-protein is responsible for fusion of the virus and host cell membranes, viral penetration, and hemolysis. The H-protein is responsible for the binding of virions to cells. Unlike the snake-like Ebola virus or the egg-shaped H1N1 influenza virus , the form of the coronavirus varies. It is shown here as spherical. Its surface is studded with an average of about 90 spike proteins in red that give it its name. Among viruses whose genetic material is made of RNA, coronaviruses have the largest genomes.
But compared with DNA viruses, coronaviruses are generally smaller, less complex and less accurate in replicating themselves. Membrane proteins are shown here as clusters of pink and purple atoms sitting on the surface of the virus. They help the virus to identify and then bind to receptor sites on the cells it seeks out. They also help shield the virus from the immune system by casting a kind of cloud over it.
And they prevent coronaviruses from clumping together in ways that would reduce their efficiency. When coronaviruses have been altered in a lab to lack these envelope proteins , the resulting viruses have been unable to copy themselves quickly or accurately.
Scientists say vaccines to thwart the coronavirus and therapies to treat COVID might focus on disrupting the supply or function of this enigmatic protein. In the image above, immune system proteins called antibodies are shown orbiting the coronavirus. Even though we try to stay away from pathogens, many other bacteria and viruses are helpful. Bacteria that live in the oceans and soil are important to cycle nutrients in the environment.
Other bacteria turn milk into yogurt or cheese for us to eat. There are even some helpful viruses and bacteria that live inside you, called mutualists. Some viruses and bacteria inside you actually help guard your body against more dangerous infections, and other viruses can help plants survive cold or droughts better. If we were able to see viruses with our eyes, we would see that they are all around us. Luckily, your immune system can remove most viruses that make you sick.
In some cases, doctors give us medicines that can slow down difficult viruses to help your immune system fight them. There are many ways viruses can get into the body. Insects, like mosquitoes, can spread some viruses between people they bite. More often, the viruses that cause colds come from infected people through a sneeze or cough. Once out, they can get in your body when you inhale them from the air or touch a surface they are stuck to.
There are ways to stay healthy and to keep others from getting sick from viruses. The best way is to wash your hands. The soap can break open the fatty envelope that surrounds some viruses, destroying them. When you are sick, you can protect others by covering your mouth and nose when you cough. Instead, use your upper arm and shoulder to cover your mouth and nose. Think about this — even if we could magnify a cell until it was the size of a basketball, a virus would still only be about the size of a single period on this page.
The most simple viruses have only two parts: 1 a genome DNA or RNA that is a blueprint with instructions for making more viruses and 2 a capsid protein shell that protects the genome. Viruses also often have proteins called receptors that stick out of the shell, and help the virus sneak inside cells. Many viruses that infect humans and animals also have an envelope, something like a cell membrane, around the capsid and genome.
These are just the basics, though. Below are images taken with an electron microscope showing you just a few of the many different shapes of viruses. You might not think that simple viruses could take over your complex cells, but they do all the time.
Coronavirus particles are artificially colored in blue. But, these images are hard and labor-intensive to produce and for most people with COVID, pictures like this will never be made.
With some infectious diseases, actually looking down microscopes to identify the type of pathogen is a common way for microbiologists to diagnose patients. However, viruses are simply too small to see using most conventional microscopes, so this technique is used mostly for bacterial and fungal infections. The largest viruses are about nm in diameter which means that you could only see them as dots in a light microscope. The new images are taken by microscopes which use electrons and magnets to focus and produce images, rather than light and glass lenses found in most conventional microscopes.
They are often large compared to most conventional laboratory microscopes and also require highly-trained, specialist users.
0コメント