Microbiology: Chapter 1-6 Test

Microorganisms

are entities that are too small to be seen with the unaided eye.

Examples of Microbes

Bacteria, Viruses, Protozoa, Fungi, Algae, and Larvae of Helminths

Pathogenic Microbes

cause disease.

Microorganisms are Beneficial

They: Decompose Waste

Are producers of oxygen by photosynthesis

Provide a food source for many other organisms

Produce fermented foods such as vinegar, cheese and bread

Produce anitbiotics and vaccines

Microorganisms are Beneficial by

Producing industrial chemicals such as ethyl alcohol, acetone, and enzymes used in cleaners.

Linneaus

established the system of scientific nomenclature.

Genus and Species

Two names of any organism.

Serotypes

Most bacterial species contain subspecies or what which are variations within a species.

Three Domains

Eubacteria

Archaea

Eukaryotes

Bacteria

Prokaryotes

Unicellular

Peptidoglycan is found in their cell wall

Reproduce by binary fission

Extremely diverse

What do bacteria do for energy?

For energy, bacteria may use organic chemicals, inorganic chemicals, or photosynthesis depending on species.

Archaea

Prokaryotes similar to bacteria

Unicellular

Lack peptidoglycan

Usually live in extreme environments

Have not changed structure and physiology for centuries

Fungi

Eukaryotes

Chitin in cell walls

Use organic chemicals for energy (not photosynthetic)

Larger than bacteria, some reproduce sexually

Many produce reproductive structures like mushrooms and sporangia.

Protozoa

Eukaryotes

Absorb or ingest organic chemicals

Very few species are photosynthetic

Some are serious parasites in humans

Mostly unicellular and motile via pseudopods, cilia, or flagella

Algae

Eukaryotes

Cellulose cell walls

Unicellular and Multicellular forms usually found in aquatic systems

Use photosynthesis for energy

Produce molecular oxygen and organic compounds

Are a food source for many organisms

Viruses

Acellular (non-living)

Consist of DNA or RNA core

Obligate intracellular parasites

When are viruses replicated?

Viruses are only replicated when they are in a living host cell

Helminths

Eukaryotes

Multicellular animals; most are not parasitic

When were the first microbes observed?

1600s

Robert Hooke

1665; reported that living things were composed of cells.

Cell Theory

all living things are composed of cells and come from preexisting cells.

Antoni Van Leeuwenhoek

1673; observed and described living microorganisms.

He observed teeth scrapings, rain water, and peppercorn infusions.

Louis Pasteur

"Father of Microbiology"

1861; he demonstrated that microorganisms are present in the air with his S-shaped flask

Disproved spontaneous generation

Pasteurization

Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine.

Ignaz Semmelwise

1840s; advocated hand washing to prevent transmission of pueperal fever from one OB patient to another.

Joseph Lister

1860s; used a chemical disinfectant to prevent surgical wound infections.

Robert Koch

1876; provided proof that a bacterium, (Bacillus anthracis) causes Anthrax and developed his own postulates.

Koch Postulates

used to prove that a specific microbe causes a specific disease.

Edward Jenner

noticed that milkmaids never contracted smallpox, he believed due to their exposure to cowpox.

1796; he inoculated a person with cowpox virus to protect them from smallpox virus.

Antibiotics

chemicals produced by bacteria and fungi that inhibit or kill other microbes.

Paul Ehrlich

1910; developed and synthetic arsenic drug, salvarsan, to treat syphilis.

Sulfonamides

1930s; were synthesized and are commonly prescribed as sulfa-drugs

Alexander Fleming

1928; discovered the first antibiotic on accident; penicillin.

Biotechnology

is the use of microbes to produce food and chemicals

Genetic Engineering

through this, bacteria and fungi can produce a variety of proteins including vaccines and enzymes.

Gene Therapy

missing or defective genes in human cells can be replaced by this.

Genetically Modified Bacteria

are used to protect crops from insects and freezing.

Resistance

the ability of the body to ward off disease.

Zaccharias Janseen

is credited with making the first compound microscope in the 17th century.

Joseph Listers Father

made the first one capable of viewing microbes in the mid-19th century.

Compound Microscope

the image from the objective lens is modified again by an ocular lens.

Illuminator

Light source

Condenser

lenses that direct light rays through the specimen.

Resolution

the ability of the lenses to distinguish two points and fine detail and structure.

Refractive Index

is a measure of the light-bending ability of a medium.

Immersion Oil

is used to keep light from bending.

Brightfield Illumination

Dark objects are visible against a bright background

Most small specimens are killed and stained with colored dyes.

Some larger and motile specimens may be viewed.

Darkfield Illumination

Light objects are visible against a dark background

Used to examine living or unstained organisms suspended in liquid.

Smear

a thin film of a solution of microbes on a slide

Chromophore

dye that carries a charged particle

Mesophiles

25-40 degrees celsius

Thermophiles

70-80 degrees celsius

Pyschrophiles

15 degrees celsius

Psychrotrophs

22 degrees celsius

Carbon

is required by all organisms to form structural organic molecules and as an energy source.

Nitrogen

is a limiting factor in many ecosystems and is found in amino acids and proteins

Sulfur

is found in amino acids, thiamine, and biotin.

Phosphorus

is found in DNA, RNA, ATP, and membranes.

Oxygen

is utilized by obligate aerobes and facultative anaerobes

Obligate Anaerobes

need the absence of O2; many are killed by it.

Facultative Anaerobes

can also grow without oxygen (many are fermenters)

Microaerophiles

require strict limited amounts of O2 to survive.

Reproducing Media

contain chemicals that combine O2.

Culture Media

nutrients prepared for microbial growth.

Sterile

no living microbes

Inoculum

introduction of microbes into medium

Culture

microbes growing in or on culture medium