BACTERIA AND ANTIBIOTICS
LAB REPORT

Biology 09 period 8
March 12, 2013

Introduction:

1. Eubacteria
-Has cell wall with peptidoglycan
-They can live nearly anywhere on earth (sky to underground)
-Unicellular
-Prokaryotic
-Reproduce Asexually

Archaebacteria

-Cell wall without peptidoglycan
-Live in environments without oxygen (anaerobic)
-Prokaryotic
-Unicellular
-Reproduce Asexually
-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:
PHOTOAUTOTROPHS
PHOTOHETEROTROPHS
CHEMOAUTOTROPHS
CHEMOHETEROTROPHS

3.

4. Many bacteria are heterotrophic which is to thrive off other organisms. The type of bacteria that causes disease are heterotrophic parasites. There are also many harmless bacterial parasites, many of which can be helpful to their hosts. Autotrophic bacteria manufacture their own food by chemosynthesis and photosynthesis. In aerobic respiration a series of reactions convert glucose to carbon dioxide and water and give off energy. Free oxygen is required as the final acceptor for electrons and hydrogen to form water. Bacteria, able to grow in the presence of oxygen, are called aerobic bacteria. Pseudomonas is an example of aerobic bacteria. In anaerobic respiration free oxygen isn’t required. Organic compounds are the final electron acceptors in anaerobic respiration. The bacteria able to grow in the absence of oxygen are called anaerobic bacteria. Some bacteria are neither aerobic nor anaerobic, but facultative E.coli is an example facultative anaerobic bacteria. Facultative bacteria grow either in the presence or absence of oxygen. All prokaryotic bacteria reproduce asexually. Bacterial reproduction most commonly occurs by a kind of cell division called binary. 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