Micro 201L Exam

Iowa State University Microbiology 201

Microbiology

The study of the microbial world requiring a microscope: bacteria, archaea, fungi, protozoa, algae, viruses, viroids, and prions.

Bacteria

A living organism that is prokaryotic (unicellular).

Archaea

A living organism that is prokaryotic (unicellular). They have an ability to grow in extreme environments.

Prokaryote

A unicellular organism. Single-celled organism consisting of a prokaryotic cell; members of the domains Bacteria and Archaea are Prokaryotes.

Eukaryote

Organism composed of one or more eukaryotic cells; members of the domain Eukarya are Eukaryotes. Algar, Protozoa, and Fungi.

Fungi

A living organism that is a eukaryote (unicellular or Multicellular). Decomposers. Harvest energy from organic material.

Protozoa

A living organism that is a eukaryote (unicellular) [protist]. Generally larger than prokaryotes.

Algae

A living organism that is a eukaryote (unicellular or multicellular). [protist]. Photosynthetic.

Leeuwenhoek

Originally sold fabric; founder of microbiology; designed the hand-held microscope; first to observe and draw microbes

Pasteur

Established microbial role in fermentations (alcohol), refuted the theory of spontaneous generation, helped establish the germ theory of disease, developed pasteurization process, and developed vaccines for cholera, anthrax, and rabies. (swan-necked flask experiment proved that life comes from pre-existing life).

Koch

Showed that anthrax disease was caused by a bacterium, established the germ theory of disease (koch’s postulates), and made many technological breakthroughs (found the solidifying agent agar).

Koch’s Postulates

Proof that a particular microbe causes a particular disease. 1. The microorganism must be present in every case of the disease. 2. The microorganism must be grown in pure culture from diseased hosts. 3. The same disease must be produced when a pure culture of the microorganism is introduced into susceptible hosts. 4. The microorganism must be recovered from the experimentally infected hosts.

Spontaneous Generation

The idea that worms and other forms of life that arise from non-living material.

Germ Theory of Disease

One organism causes one disease. Proven by Koch’s Postulates.

Isolation

Isolation methods, like the streak plate and loop dilution, are methods to separate individual microbial cells. Isolating these cells, with the right nutrients and conditions, will multiplu to form a colony that can be further assessed.

Culture Medium

A substance containing nutrients in which cells or microorganisms can be grown. whatever you use to grow your microbes, liquid (test tube or flask) or solid (petri dish). Agar + AA/sugars (eat) + Salts (osmotic balance + antibiotics (selectively grow certain microbes) +Indicator +water (broth) or solid.

General Medium

non-selective, all species can grow.

Differential Medium

certain species exhibit a particular characteristic, like color. (ex. Bacteria ferment sugar and produce acid, which turns the pH indicator red).

Selective Medium

Only certain species can grow. Inhibits the growth of some species while allowing the growth of others (might use an antibiotic).

Agar

Only solidifies the media. A polysaccharide extracted from seaweed is used to solidify culture media.

Pure Culture

A population descended from a single cell and therefore contains only one species.