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54 terms

Introduction to Microbiology

Lesson 1
STUDY
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agar
A gelatin-like solidifying agent used in laboratory culture media.
animalcules
Tiny, rapidly swimming animals 1st observed under a
microscope by Antonie van Leeuwenhoek in the 1670s.
biotechnology
A process widely employed by various industries that uses
microbes to solve biological problems; to produce large
quantities of useful items, such as antibiotics, vitamins, and food supplements; and to degrade toxic materials (especially in raw sewage).
germ theory of disease
The belief that microbes will grow in humans and are the cause
of diseases that spread from person to person and town to town.
hypothesis
A suggested explanation for observations relating to a specific scientific phenomenon.
Koch postulates
Four requirements developed by Robert Koch in the 1870s that
must be satisfied in order to establish that an organism is the
cause of a disease: show that a given organism exists in animals
infected with the specific disease but not in animals that are not
infected with the disease; obtain a pure culture of the organism;
produce the same symptoms seen in the infected animals by
inoculating healthy animals with this isolate; and isolate the
identical microbe from the newly infected animal.
lysozyme
Enzyme discovered by Alexander Fleming in the early 20th
century that destroys bacteria by degrading bacterial cell walls.
microbes
Tiny, medically relevant organisms including prions, viruses, bacteria, fungi, and parasites.
microbiology
The study of a variety of organisms that require a microscope to be seen.
penicillin
The 1st true antibiotic used to kill bacteria during the 20th
century.
pure culture
A group of microorganisms consisting of a single species of cells with no external contamination.
scientific method
A logic-based process scientists use to make observations about a specific phenomenon, develop a hypothesis to explain these observations, and arrive at provable conclusions.
spontaneous generation
The notion that microbes develop without any cellular parentage.
bacteria
Millions of forms of small, single-celled living microorganisms.
binomial system
A 2-titled naming system for organisms that includes the
organism's genus and species.
biovars
Biological variants that exist between 1 or several genes in an organism.
cyanobacteria
Once thought to be blue-green algae, this form of bacteria uses
sunlight to produce carbohydrates and fix nitrogen from the air,
creating a bad taste and odor in drinking water supplies during
summertime. Cyanobacteria perform a major role in the
worldwide production of oxygen.
domain
The highest level of nomenclature division.
eukaryotes
The various species of the domain Eukarya, which includes all
organisms except bacteria. Eukaryotes contain a true (eu)
nucleus.
nomenclature
A process of naming and classifying microbes.
prokaryotes
Bacterial organisms that have no nucleus. The term derives from the Greek terms "pro" (meaning before) and "kary" (meaning nucleus).
serovars
Serological variants that exist between 1 or several genes in an organism.
strains
Variations between organisms that exist in 1 or several genes.
taxonomy
The practice of naming and classifying microbes or other living organisms.
brightfield microscopy
A technique for making microbes visible by placing them on a glass slide and magnifying them by a light microscope.
differential stain
A staining procedure that differentiates between 2 common types of bacteria.
electron microscopy
High-resolution microscope observation that uses electrons to illuminate tiny virus particles.
medium
A nutritious extract or mixture of materials that will support the growth of microbes.
scanning electron microscopy (SEM)
A viewing process in which scattered electrons are detected and the object's surface is reconstructed by computer technology; especially good for visualizing surface structures.
transmission electron microscopy (TEM)
A process in which electrons pass through a specimen and heavy
metals pile up around the virus and scatter electrons. This leaves
dark areas that reflect the viral outline on the viewing screen.
acids
Substances that have an excess of H+ ions.
adenine
A base that opposes thymine (T) within the 2 strands of DNA
bases
Substances that have an excess of OH ions.
cholesterols
Waxy, lipid substances found in the bloodstreams and cells of animals.
chromosome
A single piece of double-stranded DNA composed of thousands of genes. The 2 strands are complementary so that they always pair in a certain order.
cytosine
A base that opposes guanine within the 2 strands of DNA.
deoxyribonucleic acid
A variety of nucleic acid and, along with ribonucleic acid, 1 of 2 types of molecules that encode genetic information.
enzymes
Proteins that serve to break down complete nutrients into
smaller, useful molecules according to the energy requirements of each cell.
ergosterols
Lipid components found in fungi that serve the same purpose as cholesterol in animals.
gene
A string of 3-letter codons that is usually 300 to 1000 base pairs long.
guanine
A base that opposes cytosine within the 2 strands of DNA.
lipids
Relatively small macromolecules that span the membrane of every cell. Most membrane lipids contain phosphate and are called phospholipids.
macromolecules
Large types of molecules found in numbers of 1 to 100,000
copies per cell. Macromolecules include proteins,
polysaccharides, nucleic acids, and lipids.
messenger RNA
A single-strand structure that contains the sugar ribose and
uridine (U) in place of the thymine present in DNA. Messenger
RNA is used as the actual template for protein synthesis.
nonpolar
A molecule in which there is no charge differential between each end.
nucleic acid
A macromolecule consisting of a sugar-phosphate repeating structure that is usually large and can be millions of units long. Each sugar has 1 of 4 possible basic molecules, called bases or nucleotides, attached.
polar
A molecule in which there is a positive charge at 1 end and a negative charge at the other.
polysaccharides
Macromolecules in which sugars are polymerized into long chains. Polysaccharides provide strength to microbial cells to keep them from breaking open.
proteins
Macromolecules that comprise 100 to 600 amino acid residues. The majority of proteins are enzymes.
ribonucleic acid
A variety of nucleic acid and, along with deoxyribonucleic acid, 1 of 2 types of molecules that encode genetic information.
sterols
A type of lipid useful as targets for antibiotic therapy of fungi.
thymine
A base that opposes adenine (A) within the 2 strands of DNA.
translation
The process of protein synthesis.
uracil
A material found in messenger RNA, as opposed to the thymine that exists in DNA.