Chapter 1 - The Invisible World Flashcards
What is the study of microorganisms too small to be seen?
Microbiology
Microorganisms include:
- Bacteria
- Viruses
- Fungi
- Protozoa
- Helminths (worms)
- Algae
Bacteria-like organisms have existed on earth for about ___ _______ _____
3.5 billion years
Simple cells
Prokaryotes (pre-nucleus)
Complex cells
Eukaryotes (true nucleus)
What are the two cell lines?
- Prokaryotes
2. Eukaryotes
Microscopic, unicellular organisms, lack nuclei and membrane-bound organelles
Prokaryotes
Unicellular (microscopic) and milticelluar, nucleus and membrane-bound nucleus
Eukaryotes
Avascular, parasitic particles composed of a nucleic acid and protein
Viruses
What makes RNA?
Nucleolus
What makes proteins?
Rough ER
What makes lipids?
Smooth ER
The flow of energy and food through the earth’s ecosystems
Photosynthesis and decomposition
Light fueled conversion of carbon dioxide to organic material
Photosynthesis
Breakdown of dead matter and wastes into simple compounds
Decomposition
Production of foods, drugs, and vaccines using living organisms
Biotechnology
Manipulating the genes of organisms to make new products
Genetic engineering
Using living organisms to remedy an environmental problem
Bioremediation
Majority of microorganisms live a free existence, are relatively ________ and often _________
Harmless and often beneficial
Many microorganisms have close associations with other _________
Organisms
Microorganisms that do harm
Pathogens
Nearly _____ different microbes cause diseases
2,000
There are __ _______ new infections/year worldwide
10 billion
There are __ _______ deaths from infections/year worldwide
13 million
There are _________ of microbioligists
Thousansds
Prominent discoveries include:
- Microscopy
- Scientific method
- Development of medical microbiology
- Microbiology techniques
An early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc.)
Spontaneous Generation
Louis Pasteur eventually disproved spontaneous generation and proved the
Theory of Biogenesis
the idea that living things can only arise from other living things
Theory of Biogenesis
- Dutch linen merchant
- First to observe living microbes
- Single-lens magnified up to 300X
Antoni van Leeuwenhoek (1632-1723)
Approach taken by scientists to explain a certain natural phenomenon
Scientific Method
What are the 5 steps of the scientific method?
- Make observation
- Form hypothesis
- Run experiments
- Analyze data
- Draw conclusion
What word are you never supposed to use with the hypothesis?
Prove
A tentative explanation that can be supported or refuted
Hypothesis
Deductive approach “If…, then….”
Hypothesis
A lengthy process of experimentation, analysis, and testing either ________ or _______ the hypothesis
Supports or refutes
If hypothesis is supported by a growing body of evidence and survives rigorous scrutiny, it moves to the next level of confidence - it becomes a
Theory
If evidence of a theory is so compelling that the next level of confidence is reached, it becomes a
Law or principle
Results must be _________ and ________ by other investigators
Published and repested
Early experiments led to the realization that microbes are __________
Everywhere
Resulted in the use of sterile, aseptic, and pure culture techniques
Germ theory of disease
Cleans using 15 ppsi and 121 degrees Celsius
- Steam
Autoclave
Cleans by burning
Incineraton
John Tyndall and Ferdinand Cohn each demonstrated the presence of ____ resistant forms of some microbes
Heat
Cohn determined these forms to be heat-resistant bacterial
Endospores
Requires the elimination of all life forms including endospores and viruses.
Sterility
The human body is a source of _________
Infection
Observed that mothers of home births had fewer infections than those who gave birth in hospitals
Dr. Oliver Wendell Holmes
Correlated infections with physicians coming directly from the autopsy room to the maternity ward
Dr. Ignaz Semmelweis
Introduced aseptic techniques to reduce microbes in medical settings and prevent wound infections
Joseph Lister
- Involved disinfection of hands using chemicals prior to surgery
- Use of heat for sterilization
Reduce microbes in medical settings and prevent wound infections
Many diseases are caused by the growth of ________ in the body and not by sins, bad character, or poverty, etc. The germ theory of disease helped support this
Microbes
Two major contributors to the germ theory of disease:
Louis Pasteur and Robert Koch
- Showed microbes caused fermentation and spoilage
- Disproved spontaneous generation of microorganisms
- Developed pasteurization
- Demonstrated what is now known as Germ Theory of Disease
Louis Pasteur (1822-1895)
- Established Koch’s postulates - a sequence of experimental steps that verified the germ theory
- Identified cause of anthrax, TB, and cholera
- Developed pure culture methods
Robert Koch (1843-1910)
A sequence of experimental steps that verified the germ theory
Koch’s postulates
Organizing, classifying, and naming living things
Taxonomy
Orderly arrangement of organisms into groups
Classification
Assigning names
Nomenclature
Determining and recording traits of organisms for placement into taxonomic schemes
Identification
What are the levels of classification
- Domain - Archaea, Bacteria, & Eukarya
- Kingdom
- Phylum or Division
- Class
- Order
- Family
- Genus
- Species
What are the three domains?
- Archaea
- Bacteria
- Eukarya
Capitalized
Genus
Lowercase
Species
Italicized or underlined
Genus and species
Inspiration for names is extremely varied and often ___________
Imaginative
Natural relatedness between groups of organisms
Phylogeny
- All new species originate from preexisting species
- Closely related organism have similar features because they evolved from common ancestral forms
Evolution
Evolution usually progresses toward _______ __________
Greater complexity
True bacteria
Bacteria
Odd bacteria that live in extreme environments, high salt, heat, etc.
Archaea
Have a nucleus and organelles
Eukarya
