Sheenin2

// Sheenin // **1. Describe the difference between leukocyte and white blood cells.** Leukocytes are a more specific term for white blood cells. Leukocytes refers to the cells in our body that is part of our immune system, and they play a role by fighting off the virus as soon as possible. On the other hand, white blood cells are simply one of the two kinds of cells in our body, and the other kind is red blood cells.

**2. The term proteins are frequently used in the study of immunology. Explain the term/concept proteins.** Proteins could be antibodies, Major Histocompatibility Complexes, and many more. The term proteins is used to describe molecules that “digest” other cells. Just like digestion, proteins are the ones which our body breaks down into simpler pieces, into amino acids and peptide chains. In immunology, proteins are also use to break down the unwanted cells into simpler protein molecules for our body to bring it away. For example, when an antigen is spotted and engulfed into the membrane of the phagocytes, it would be broken down into simpler forms by the highly-reactive protein molecules in another vesicle in the phagocytes.

**3. Explain why the Black Death virus, which has caused millions of deaths, was deadly using concepts of immunology.** The Black Death virus, was not known to the world before it started to be cancerous and infected a huge part of Europe. The doctors have not been prepared for a virus like this, so there were no medications that an infected person can take, to help the body fight off the infection. There were also no vaccines for the people to build up immunity to that virus. So, this virus was completely new to the body, and the body could not learn to fight it off so quickly because it is very strong. The body takes maybe about hundreds, or even thousands of antibodies of different variable combinations, to “bump” into this antigen, before the one with the perfect variable combinations would bump into their matching antigen. However, since that this Black Death virus was a sudden illness, the body might take more than thousands of antibodies - since that there are about 10^ 10 kinds of antibodies in our body’s immune system - before they can finally match one another. However, this process can be long and the virus could have already infected our cells before our immune system can match them with the correct cells.

**4. The recent bird flu virus, H7N9, has a 20% fatality rate if one is infected.** This term means that there are about 20% of people had died from this virus in each year.
 * 1) What does it mean - 20% fatality rate?

This virus is “mutated”, so it has different DNA structures, that could have adapted and be immune to certain type of medications. Then, doctors will need to come up with a new medication that the new virus cannot fight against, in order to fight off the virus.
 * 1) How is this virus different from a common flu virus?

One way is to take a vaccine beforehand, so that our body can learn how to fight off this virus and build up immunity to it. Vaccines contains either severely weakened, or completely inactivated viruses, that are injected into our body. Our body would responds to this virus as if it is a real virus. In the specific immunity, it will be attached to either a B cells or a Cytotoxic T cells, depending on what kind of damage the virus had done to our immune system. The B cells or Cytotoxic T cells would be patrolling our body, and if the antibody with the right protein combination happens to meet the antigen, then they will attached to the antibody. The cell that the antibody is bounded to, will be now activated, and produces memory and effector cells. Memory cells has the ability to stay in our body and live for a longer period of time. Effector cells would simply keep producing that kind of antibody, since that it is a plasma cell. These free antibodies will roam around in our body, also keeping watch of that one specific antigen. Now, if the real virus comes in, it would be prepared and there would be many more copies of the antibody to fight off the infection even quicker before it can make us sick. This is building immunity, through vaccines. Therefore, we can be prevented against such fatal viruses.
 * 1) Are there ways to prepare our body immune system against such fatal, deadly virus?

d) The bird flu virus wasn't infectious to humans before; explain why it suddenly turned viral and harmful to humans. The bird flu virus in general, have been around in the world for a long time. After the infected people are given the same medications over and over, this virus could easily have adapted and be stronger to overcome the effects of the medications. This is called mutations of virus. The change of DNA structure of the virus could make it stronger and immune to certain medications, especially antibiotics, which human have been consuming for unnecessary purposes these days. Antibiotics have been developing new ones, however, the speed of us abusing the usages more antibiotics is faster than the rate of new antibiotics productions by the doctors. Now, since that they are no more antibiotics to kill the virus, our body cannot fight if off, so the virus will become viral and fatal to us humans.

The virus must be stronger, which again means a change of DNA structure. The virus must be strong enough to be able to survive not only in human bodies, but also in our everyday products or tools, in order to be transmitted from human to human.
 * 1) Right now, the flu is unable to infect a person through human to human transmission; if it can infect through human to human transmissions, what could have changed in the virus?