2 Bacteria Background - BACKGROUND INFORMATION for LAB...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 BACKGROUND INFORMATION for LAB EXERCISE #2 What is the difference between genetic diseases, diseases of aging, and infectious diseases? Answer: Today’s lab examines microbes ( bacterial, fungal, protozoan ), “good” or “bad”. Although humans have long observed the devastating effects of infectious diseases, the microscope made it possible to see the “bad microbes,” known as germs or pathogens. Researchers use Koch’s Postulates to identify infectious agents in disease (see Lab 1). When infectious organisms are smaller than can be seen by the naked eye, they are referred to as “ microbes .” The term " disease " refers to conditions that impair normal tissue function. For example, cystic fibrosis, atherosclerosis, and measles are all considered diseases. However, there are fundamentally different causes for each of these diseases. Cystic fibrosis (CF) is due to a specific genotype that results in impaired transport of chloride ions across cell membranes, leading to the production of abnormally thick mucus. Thus, CF is most accurately called a genetic disease , one that would be inherited from one’s parents. Atherosclerosis, which can lead to heart attacks and strokes, may be considered a disease of aging , because it typically becomes a problem later in life after plaques of cholesterol have built up and partially blocked arteries. In contrast, measles is an infectious disease because it occurs when an individual contracts an outside agent, the measles virus. An infectious disease is a disease that is caused by the invasion of a host by agents whose activities harm the host's tissues (that is, they cause disease) and can be transmitted to other individuals (that is, they are infectious). HISTORY AND CLASSIFICATION OF MICROBES What are microbes and how did we know that Erwinia was a microbe? Answer: Last week, you had a chance to make observations about a microbe called Erwinia carotovora . You saw how this infectious agent caused a disease in potatoes known as “ soft rot.” You determined it was the causal agent using Koch’s Postulates. But, were you certain at the time whether this causal agent was a bacteria, fungus, virus, of protozoa. It wasn’t until the invention of the microscope around 1590 that scientists were even able to see the world of microbes. But, once they were, then there was a need to understand more about the similarities and differences among these microorganisms. Using information from last week’s lab, compare the dates of the invention of the microscope and the work of Koch. What other progress was made in the world of science between these two dates? What were scientists doing? (Sadava, 5) Answer: 1590, two Dutch eye glass makers, Zaccharias Janssen and son Hans Janssen experimented with multiple lenses placed in a tube. The Janssens observed that objects viewed in front of the tube appeared greatly enlarged, creating both the forerunner of the compound microscope and the telescope. 1665 – English physicist, Robert Hooke looked at a sliver of cork through a microscope lens and noticed
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/18/2011 for the course CHEMISTRY 209 taught by Professor Cohen during the Spring '11 term at Pittsburg State Uiversity.

Page1 / 17

2 Bacteria Background - BACKGROUND INFORMATION for LAB...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online