BACTERIA AND ANTIBIOTICS
Biology 09 period 8
March 12, 2013
-Has cell wall with peptidoglycan
-They can live nearly anywhere on earth (sky to underground)
-Cell wall without peptidoglycan
-Live in environments without oxygen (anaerobic)
-Oldest bacterial form
-Unique lipids in their cell membrane
-DNA sequence is more like other Eukaryotes than other bacterial types (eubacteria)
2. Bacteria are classified into four groups:
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Binary fission results in the formation of two bacterial cells that are genetically identical. During binary fission, the single DNA molecule replicates and both copies attach to the cell membrane. Then, the cell membrane extends between the two DNA molecules. Once the bacterium just about doubles its original size, the cell membrane begins to pinch inward. A cell wall then forms between the two DNA molecules dividing the original cell into two identical “daughter” cells.
5. Antibiotics are drugs/medications used to treat infections caused by bacteria. Bacteria are microscopic organisms, some of which can cause illnesses. Some bacteria are harmless, while others can be good for us. Before bacteria can multiply and cause symptoms, the body's immune system can usually destroy them. We have special white blood cells that attack harmful bacteria. Even if symptoms do occur, our immune system can usually cope and fight off the infection. There are occasions, however, when it is all too much and some help is needed from antibiotics.
Although there are a number of different types of antibiotics they all work in two different ways. A bactericidal antibiotic kills the bacteria. A bactericidal usually either interferes with the formation of the bacterium's cell wall or its cell contents. A bacteriostatic cuts off the possibility of the bacteria multiplying.
6. Human immune systems have a number of ways to fight infections or to prevent them. The human body’s immune system doesn’t just include white blood cells, which attempt to catch and destroy germs, but a variety of mechanisms that stop germs from creating infection. In most cases, humans have certain properties in their bodies that are called innate immunities, allowing bodies to fight infections at virtually all times. For example, the skin, our largest organ, is constantly fighting infections, or warding off infection by acting as a barrier against foreign, non-human cells. Other parts of our bodies, or contents in our bodies are always on guard to fight infections. The gut and stomach contain mucus that can trap small numbers of foreign bacterial cells, keeping the body from becoming infected. Human bodies use a variety of acids in organs that create hostile environments for foreign cells. We also host helpful bacteria in our bodies that help keep other bacteria entering the body in check.
7. Genetic engineering is the process of manually adding new DNA to an organism. The goal is to add one or more new traits that are not already found in that organism. Examples of genetically engineered (transgenic) organisms currently on the market include plants with resistance to some insects, plants that can tolerate herbicides, and crops with modified oil content. Bacteria plays an important role in genetic engineering. As we already know that bacteria genome is easy to manipulate and they can be mutated easily. Moreover their frequency of multiplication is very high. So we can mutate a bacterium and...