Brief History of Microbiology

Unit 1 Study Guide

Chapter 1 Brief History of Microbiology

1. Define the terms microorganism and microbiology. Describe the role and impact of microbes on the earth.

Microorganism - A living thing ordinarily too small to be seen without magnification; an organism of microscopic size.

Microbiology - A specialized area of biology that deals with living things ordinarily too small to be seen without magnification, including bacteria, archaea, fungi, protozoa, and viruses.

Microbes Affect the Planet

Single celled organisms that arose 3.5 billion years ago

Bacteria, archaea and eukarya arose from this ancestor.

Eu-kary: true nucleus

Pro-kary: before nucleus

Cause Disease

Atmosphere: 70% of oxygen is from microbes

Nitrogen gas incorporated by microbes

Decomposers

Break down things

Organic material (dead things) broken down to parts

Ex. fertilizer

2. Identify multiple professions that use microbiology. Explain ways that humans manipulate organisms for their own uses.

Medical Microbiology- This branch deals with microbes that cause diseases in humans and animals. Researchers examine factors that make the microbes virulent and mechanisms for inhibiting them.

Public Health Microbiology and Epidemiology - These branches monitor and control the spread of diseases in communities. Institutions involved in this concern are the U.S. Public Health Service (USPHS) with its main agency, the Centers for Disease Control and Prevention (CDC) located in Atlanta, Georgia, and the World Health Organization (WHO), the medical limb of the United Nations.

Immunology - This branch studies the complex web of protective substances and cells produced in response to infection. It includes such diverse areas as vaccination, blood testing, and allergy.

Industrial Microbiology - This branch safeguards our food and water, and also includes biotechnology, the use of microbial metabolism to arrive at a desired product, ranging from bread making to gene therapy. Microbes can be used to create large quantities of substances such as amino acids, beer, drugs, enzymes, and vitamins.

Agricultural Microbiology - This branch is concerned with the relationships between microbes and domesticated plants and animals. Plant specialists focus on plant diseases, soil fertility, and nutritional interactions. Animal specialists work with infectious diseases and other associations animals have with microorganisms.

Environmental Microbiology - These microbiologists study the effect of microbes on the earth’s diverse habitats. Whether the microbes are in freshwater or saltwater, topsoil or the earth’s crust, they have profound effects on our planet. Subdisciplines of environmental microbiology are Aquatic microbiology—the study of microbes in the earth’s surface water Soil microbiology—the study of microbes in terrestrial parts of the planet Geomicrobiology—the study of microbes in the earth’s crust and Astrobiology (also known as exobiology)—the search for/study of microbial an

3. Emphasizing the differences between developed and developing countries relative to infectious diseases.

Read Section 1.4

4. Differentiate among the major groups of microorganisms: bacteria, archaea, and eukaryotes.

Bacteria - prokaryotic cells.

Single cells, no nucleus

No organelles (cell organs)

Archaea

are made of prokaryotic cells and are unicellular.

Eukaryotes:

Have organelles with membranes (nucleus with DNA)

Fungi - mushrooms and yeasts

Protists - protozoans and algae

Animals - worms are microscopic.

5. What is the significance of the microscopy observations by Hooke and Leeuwenhoek?

Robert Hooke:

In the 1660s, Hooke studied a great diversity of material from household objects, plants, and trees; described for the first time cellular structures in tree bark; and drew sketches of “little structures” that seemed to be alive. Using a single-lens microscope he made himself.

Hooke paved the way for even more exacting observations of microbes by Antonie van Leeuwenhoek.

Antonie van Leeuwenhoek:

Leeuwenhoek constructed more than 250 small, powerful microscopes that could magnify up to 300 times.

He scraped glass to make it finer so he can use as a magnifying glass, he started looking at rainwater and plaque from teeth.

Known as the father of bacteriology and protozoology.

6. Define abiogenesis (or spontaneous generation) and biogenesis. Describe the experiments used to support or disprove abiogenesis (Redi). Explain how Pasteur used swan-necked flasks to rule out abiogenesis.

Abiogenesis - a = without, bio = life, genesis = beginning— beginning in absence of life; which embraced spontaneous generation (life can arise from nothing).

Biogenesis - beginning with life; saying that living things arise only from others of their same kind.

Redi:

Looked at appearance of maggots

Left meat out and got maggots and flies

When he covered the meat and put it in the jar he noticed no maggots so he ruled out microscopic origin.

Pasteur:

Boiled plant and meat extracts (gravey) in swan-neck flask

The open end allows gasses in and out

He left the flasks open for months = remained clear

He