Viruses
A virus is a tiny, non-living particle that enters and then reproduces inside a living cell. No organisms are safe from viruses. Viruses are non-living because they do not have all the characteristics essential for life. Viruses cannot make food, take in food, or produce wastes. The only way viruses are like organisms is that they are able to multiply. They can only multiply when they are in a living cell.
The organism that a virus enters and multiplies inside is called a host, an organism that provides a source of energy for a virus or another organism. A virus acts like a parasite, and organism that lives on or in the host and causes it harm. Almost all viruses destroy the cells in which they multiply.
The organism that a virus enters and multiplies inside is called a host, an organism that provides a source of energy for a virus or another organism. A virus acts like a parasite, and organism that lives on or in the host and causes it harm. Almost all viruses destroy the cells in which they multiply.
Virus Shape and Size:
Viruses vary widely in shape. Some are round, rod-shaped, brick-like, thread-like, bullet-like and some are even robot-like. One virus called the bacteriophage is robot-like. A bacteriophage is a virus that infects bacteria. Its name means bacteria eater. Viruses also vary in size. They are so small they can not be seen with an average microscope. They are measured in units called nanometers. One nanometer is one billionth of a meter. The smallest viruses are 20 nanometers in diameter while the largest is more than 200 nanometers in diameter.
Viruses vary widely in shape. Some are round, rod-shaped, brick-like, thread-like, bullet-like and some are even robot-like. One virus called the bacteriophage is robot-like. A bacteriophage is a virus that infects bacteria. Its name means bacteria eater. Viruses also vary in size. They are so small they can not be seen with an average microscope. They are measured in units called nanometers. One nanometer is one billionth of a meter. The smallest viruses are 20 nanometers in diameter while the largest is more than 200 nanometers in diameter.
Viruses Structure
All viruses have two basic parts: a protein coat that protects the virus and and an inner core made of genetic material. The genetic material contains the instructions for making new viruses. Some viruses are also surrounded by an additional outer membrane. The shape of the surface proteins allows the virus to attach to certain cells in the host. Like keys, a virus's proteins fit only in certain "locks," or proteins, on the surface of a host's cell. Because it is so specific a virus can only attach to one or a few types of cells.
All viruses have two basic parts: a protein coat that protects the virus and and an inner core made of genetic material. The genetic material contains the instructions for making new viruses. Some viruses are also surrounded by an additional outer membrane. The shape of the surface proteins allows the virus to attach to certain cells in the host. Like keys, a virus's proteins fit only in certain "locks," or proteins, on the surface of a host's cell. Because it is so specific a virus can only attach to one or a few types of cells.
Active and Hidden Viruses
To learn all about how active and hidden viruses work CLICK HERE.
After a virus attaches to a host cell, it enters the cell. Once inside a cell, a virus's genetic material takes over many of the cell's functions. It instructs the cell to produce the virus's proteins and genetic material. These proteins and genetic material then assemble into new viruses. Some viruses take over cell functions immediately. Other viruses wait a while.
To learn all about how active and hidden viruses work CLICK HERE.
After a virus attaches to a host cell, it enters the cell. Once inside a cell, a virus's genetic material takes over many of the cell's functions. It instructs the cell to produce the virus's proteins and genetic material. These proteins and genetic material then assemble into new viruses. Some viruses take over cell functions immediately. Other viruses wait a while.
Viruses and the Living World
Although viruses can effect humans, they also can effect other organisms. To treat some of these diseases, scientists take advantage of a virus's ability to enter a host cell in a technique called gene therapy. They add genetic material to a virus and then use the virus as a "messenger service" to deliver the genetic material to the cells that need it. Gene therapy shows some promise as a medical treatment for disorders such as cystic fibrosis. People with cystic fibrosis lack the genetic material they need to keep their lungs functioning properly. Gene therapy delivers the needed genetic material to their lungs.
Although viruses can effect humans, they also can effect other organisms. To treat some of these diseases, scientists take advantage of a virus's ability to enter a host cell in a technique called gene therapy. They add genetic material to a virus and then use the virus as a "messenger service" to deliver the genetic material to the cells that need it. Gene therapy shows some promise as a medical treatment for disorders such as cystic fibrosis. People with cystic fibrosis lack the genetic material they need to keep their lungs functioning properly. Gene therapy delivers the needed genetic material to their lungs.