Showing posts with label Cells. Show all posts
Showing posts with label Cells. Show all posts

Apr 4, 2014

Virus vs. Bacteria

Viruses and bacteria are very different and they can both be either beneficial or harmful. A virus is both living and non-living, and is incapable of reproducing on its own, while bacteria are complete, living organisms that can self-replicate. Bacteria are usually much larger, come in a wider variety of shapes, and serve in more beneficial roles than a virus.

Infections and illnesses can be viral or bacterial. We often hear the terms, and we might even have a vague idea of what they mean, but a complete understanding of the difference between the two can help you treat the illnesses they cause.

Viruses are tiny, microscopic things that exist in two different states. When they are floating in the air or lying on a table waiting for someone to come by and inhale them, they are non-living and inert. Once they are absorbed into a living host, they activate. A virus cannot replicate on its own, and requires a host cell to attach itself to in order to multiply. Some microbiologists classify viruses as microorganisms, while others don't because they are "nonliving" and describe viruses as microscopic infective agents.

After contacting a host cell, a virus will insert genetic material into the host and take over that host's functions. The infected cell continues to reproduce, but it reproduces more viral protein and genetic material instead of its usual products. It is this process that earns viruses the classification of "parasite".

However, a virus can also be useful, because a virus will naturally attach itself to a healthy living cell, a virus can be used as a delivery system when genetic material needs to be transferred to a human body. Injecting a virus with genetic material then releasing it into the body can result in the delivery and replication of cells. This type of gene therapy is still experimental, but showing progress. Some types of viruses can also target and destroy some types of bacteria, like E. coli.

Bacteria are tiny, living organisms that are not classified as either plant or animal. As such, they don’t rely on hosts in order to reproduce, and can exist, grow, and multiply outside of a living body. Few know that many bacteria not only coexist with us all the time, but help us do an array of useful things, like make vitamins, break down garbage, and maintain our atmosphere.

Bacteria consist of a single cell and have been found living in temperatures above the boiling point and in freezing cold. They consume everything from sugar and starch to sunlight, sulfur, and iron. There is a species of bacteria that can withstand blasts of radiation 1,000 times greater than would kill a human being. A gram of soil typically contains about 40 million bacterial cells. A milliliter of fresh water usually holds about one million bacterial cells.

A single bacterium contains more than a virus and can reproduce on its own. That means a cell wall, genetic material, and an appendage to propel itself. It’s different from plant and animal cells, however, as there’s no nucleus to contain the genetic material.

When magnified, a virus appears round. Bacteria can be a number of different shapes, including the ball-shaped, rod-shaped, and spiral. Within each general group of shape types, there is a wide variety that separates bacteria even further.

Because of their simplicity, a virus can be 10,000 times smaller than a bacterium. Examples of both can be found just about anywhere on Earth, in any environment.

Determining whether an illness is caused by bacteria or a virus determines how it is treated. Bacteria are vulnerable to antibiotics, while anti-viral agents are required to kill a virus, and vaccinations can help prevent them from infecting a body.

Aug 16, 2013

Chemotherapy and Hair Loss

Chemotherapy, sometimes referred to as chemo is the use of medicines or drugs to treat cancer. There are more than 100 chemo drugs. Chemo may be used to: Keep the cancer from spreading, slow the cancer’s growth, kill cancer cells that may have spread to other parts of the body, relieve symptoms such as pain or blockages caused by cancer and, in some cases, cure cancer. Different types of chemotherapy work in different ways and have different side effects. It can be administered as a pill, liquid, shot, IV, or rubbed on the skin.

Most cells in the human body divide using a process called mitosis. When a cell reaches the end of its lifespan, it gets destroyed in a pre-programmed process called apoptosis.

There are over 200 many types of cancer. All types are a result of unregulated cell growth. Cells that divide more rapidly than apoptosis can regulate is simply too much mitosis. The result is excessive tissue, known as tumors. Tumors can be localized or spread through the lymphatic system or blood stream.

Many chemotherapy drugs are administered in combinations and work by interrupting mitosis and most cannot differentiate between abnormal cancer cells and normal healthy cells. Because of this, any cells that multiply rapidly can also be affected by chemotherapy.

Fast growing cells are found in hair follicles, lining of the mouth, stomach, and bone marrow. Since these fast growing sites are also affected by chemo, the result can be hair loss, decrease in production of white blood cells, and inflammation of the digestive tract, etc. Luckily, healthy cells, like hair follicles and the others usually repair themselves, so hair loss temporary. Radiation can cause some of the same symptoms, but that story is for another day.

Nov 12, 2009

Speaking of Cells

Robert Hooke (1635 - 1702) was an English physicist. He was the first to coin the word “cell” to describe the basic unit of life (he thought that plant cells, when magnified through a microscope, looked like “cellula,” the living quarters of monks).