The Criminal Cold

Hello readers! Anyone liking the alliterative title? Yes? No? Too cheesy? Probably. Anywho I have come down with a pretty bad one of those bad boys, so while I sniff menthol tissues as though it were my lifeline, I'll be writing up on what these monsters are and why we get them!



The Common Cold

• It is a mild infection of the nose, throat, sinuses, and upper airways. It can cause a blocked nose, followed by a runny nose, sneezing, sore throat and a cough
• Colds are caused by viruses which attack the lining of the nose and throat, inflaming these areas. As they become inflamed, they begin to produce more mucus, resulting in a runny nose and sneezing. The viruses most responsible for colds belong to one of two groups, rhinoviruses and coronaviruses. Because a number of viruses can cause a cold, it's possible to have several colds, one after the other, as each one is caused by a different virus
• A cold can be spread through direct contact where if you sneeze or cough, tiny droplets of fluid containing the cold virus are launched into the air and can be breathed in by others and by indirect contact where if you sneeze and cough on an object, someone else can touch that object and may catch the cold virus if they then touch their mouth and nose
• To understand how the cold works, I'll turn to describing first how a virus works in general. They are tiny organisms, 100 times smaller than a single bacterial cell. Viruses themselves are not alive; they cannot grow or multiply on their own by they need to enter a human or animal cell and take over the cell to help them multiply. These viruses may also infect bacterial cells. The virus attacks the cell and and take over it to carry out their own life processes of multiplication and growth. The infected cell will produce viral particles are a result. 
• Viruses are not just taken into cells as they must first attach to a receptor on the cell surface. Each virus has its specific receptor, usually a vital component of the cell surface. It is the distribution of these receptor molecules on host cells that determines the cell-preference of viruses. For example, the cold and flu virus prefers the mucus lining cells of the lungs and the airways. Viruses can enter the body from the environment or other individuals from soil to water to air via nose, mouth, or any breaks in the skin and seek a cell to infect. A cold or flu virus for example will target cells that line the respiratory (i.e. the lungs) or digestive (i.e. the stomach) tracts.
• The structure of a virus has three main parts: nucleic acid (the core of the virus with the DNA or RNA which holds all of the information for the virus and that makes it unique and helps it multiply, the protein coat (capsid, the covering over the nucleic acid that protects it) and the lipid membrane (envelope, which covers the capsid, and many viruses do not have this envelope and are called naked viruses.)
• Life cycle of a basic virus:

These steps are called the lytic cycle. These include:

1. A virus particle attaches to a host cell. This is called the process of adsorption
2. The particle injects its DNA or RNA into the host cell called entry.
3. The invading DNA or RNA takes over the cell and recruits the host’s enzymes
4. The cellular enzymes start making new virus particles called replication
5. The particles of the virus created by the cell come together to form new viruses. This is called assembly
6. The newly formed viruses kill the cell so that they may break free and search for a new host cell. This is called release

Thanks for reading!