Viruses Are Parasites Using Its Host 's Cells

Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell. In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more stealthy and protected. There are two cycles in which a virus can go into: lytic and lysogenic. The lytic cycle consists of the virus attaching to a cell, injecting its DNA, and creating more viruses, which proceed to destroy the host. On the other hand, the lysogenic cycle includes the virus attaching to the cell, injecting its DNA, which combines with the cell’s DNA in order for it to become provirus. Then, the provirus DNA may eventually switch to the lytic cycle and destroy the host.

The mutation of existing viruses, the spread of existing viruses from one host species to another, and the dissemination of a viral disease from a small, isolated population that can lead to widespread epidemics.

In the article, we learn the Cache Valley virus is spreading quickly through mosquitos. In this unit we learned that viruses with RNA in their nucleic acid reproduce a lot faster than viruses that have DNA in their nucleic acid, therefore the Cache Valley virus probably has RNA in its nucleic acid. Throughout the unit we learned viruses can spread through many types of mediums such

1. In the 19th century researchers realized that some diseases such as hand foot mouth and also rabies were caused by particles that acted like bacteria. Which means virus's are alive because the particles would need t be alive to still contaminate people.

There is still a great deal of information to learn from the study of viruses and the continued exploration of the viral genome is crucial in understanding how viruses communicate, transmit from host to host and evade immune responses. The ever-change nature of the viral genome has shown us that the most dangerous viral infections of today may be undermined by newer and more effective viruses, resulting in catastrophic outcomes. Through the study of viruses, it is the hope of the scientific community to be ahead of the viral curve, preventing infections before they even

The influenza virus thrives because of its unique characteristics that allow it frequently change and undergo evolution. The influenza virus has a segmented genome meaning that each section of RNA is copied separately allowing reassortment to play a major role in the evolution of the influenza virus. When two different strands of the virus attack the same cell, both strands of RNA are copied in the nucleus. These copies then move to the cytoplasm where new viruses are compiled. Each new virus needs all eight of its genomes which can come from a copy of either of the original infecting viruses. The new virus would then have a mixture of RNA from each originating virus causing it to be different from both (Rahnama, L, et al., 2013). Reassortment causes new strains of viruses

(Silverstein: 13) There are three types of influenza, depending on their activity: type A, which is usually the cause of outbreaks; type B, which is linked to sporadic cases, and type C, which rarely causes disease reactions. (Silverstein: 54) The virus which causes influenza enters the host through the respiratory tract, and binds itself to epithelial cells. The virus causes the cell to engulf it by endocytosis, and then fuses to the wall of the endocytic vesicle, injecting the contents of the virus into the cytosol of the cell. The RNA of the virus enter the nucleus of the cell, and spur the creation of new copies of the genes. These genes, as well as new viral proteins that are created in the cell, leave the cell as fresh viruses, budding off the plasma membrane of the cell.

Viruses that maintain their genomes as several distinct RNA molecules are referred to as segmented RNA viruses. They are ubiquitous and infect a wide variety of animals, plants and bacteria. A shared feature of segmented viruses is their ability to exchange genome segments in toto during co-infection through a process called reassortment. When two or more viruses or virus strains infect the same cell, they can accidentally package each other’s genomic segments during replication into a nascent virion-producing hybrid progeny. Reassortment hence creates virions that contain a random amount of genome segments from each of the parent virions. http://www.nature.com.ezproxy.auckland.ac.nz/nrmicro/journal/v14/n7/full/nrmicro.2016.46.html.

Influenza virus can mutate in two ways, Antigenic shift and Antigenic drift. The genome is in 8 segments of RNA. Each of those 8 segments must be packaged within the viral particle in order for it to be viable. Influenza virus uses an RNA polymerase enzyme that doesn’t proofread. This allows for point mutations, incorrect bases are inserted into the genome which causes minor changes in 1 to 2 amino acids. Mutations cause slight variations in the shapes of the hemagglutinin and neuraminidase. This prevents neutralizing antibodies from binding. If a person were exposed to the new mutant strain, their immune system won’t be able to protect them. This is called antigenic drift and may happen anytime the virus replicates. Point mutations are most

The HI–Virus needs a host cell to multiply. Like all viruses the HI-Virus is not an independent organism and requires a foreign metabolism to survive. It consists of an outer envelope, which contains the docking points for the connection with the host cell. The inner capsule contains the building plan of the virus – the RNA. The HI-Virus contains also a protein coat with the enzymes. It must penetrate a human cell, introduce its hereditary informations1 and reprogram the cell that it produces the building blocks for the viral protein. The target of the HI-Virus is the cell that carries the CD4 antigen on their surface. CD4-Antigens are certain proteins molecules on the surface of the cells, which serve as receptors for the HI-Virus.

The relationship between viruses and mutations is very important. Viruses can ultimately cause cancer. Viruses can cause mutations by inserting their DNA into a cell. The inserted DNA can greatly damage or completely destroy the activity of the affected genes. Viruses can also cause mutations in indirect

Even viruses have a evolutionary history. After experiencing a plethora of mutations and sky-high rates of replication, the havoc wreaking virus known as Ebola, began to rapidly evolve. With Ebola’s mutation rates increasing exponentially, it creates countless genetic variations. These genetic variations allow evolutionary processes to spawn and flourish in the ideal environment being provided. Currently, this remarkable virus’s evolution has greatly increased in speed when compared to their past evolutions. Thus, adaptation would have been forced to repetitively occur until Ebola was almost flawlessly fitted to its current host, resulting in random mutations becoming quite rare. These adaptations paved the way to allow many variants to be

infection by viruses. When a bacterium identifies a threat from a virus, it generates two types of

This little package of mayhem consists of relatively few parts. A virus is simply a protein capsule called a capsid, sometimes surrounded by an envelope, containing a genome. The genome consists of nucleic acids arranged as DNA or less commonly, RNA. Dozens of variants of this fundamental arrangement exist with differences in the structure of the capsule and the arrangement of the genome. Small differences or changes in these components allow some viruses to continue to outmaneuver researchers, while millions of dollars are spent trying to understand and eliminate them.

material of some viruses. RNA molecules are like DNA. They have a long chain of