Module 1 Practice Questions Flashcards
When humans manipulate microorganisms to make products in an industrial setting.
Ex: Some specialized bacteria have unique capacities to mine precious metals or clean up human-created contamination.
Biotechnology
What are required for proper isolation of micros?
Inoculation tools
Agar in a petri dish
An area of biotechnology that manipulates the genetics of microbes, plants, and animals for the purpose of creating new products and genetically modified organisms (GMOs)
Ex: Recombinant DNA Tech: makes it possible to transfer genetic material from one organism to another and deliberately alter DNA.
Genetic Engineering
Refers to the ability of microorganisms–ones already present or those introduced intentionally–to restore the stability of an ecosystem or to clean up toxic pollutants.
Bioremediation
Bacteria invented photosynthesis long before the first plants appeared, first as a process that did not produce oxygen
Anoxygenic Photosynthesis
Name four disease processes where microbial infection has been implicated.
Gastric ulcers
DM1
Schizophrenia
Obesity
In general, bacterial and archaeal cells are about 10x smaller than _______ cells.
eukaryotic cells
The belief that invisible vital forces present in matter led to the creation of life.
Spontaneous Generation
The belief in spontaneous generation as a source of life.
Abiogenesis
a= without
bio= life
genesis= beginning
The belief that living arise only from others of their same kind.
Biogenesis
Demonstrated using swan flasks that dust were a source of microbes
Louis Pasteur
Probably the earliest record of microbes is in the works of
Robert Hooke
Eventually became interested in more than just thread count and used his finest lens to find “animalcules” in rainwater; he also looked at plaque on teeth.
Antonie van Leeuwenhoek
What microbes does “animalcules” refer to?
Protozoa and bacteria
Three scientists discovered little molecular “scissors” inside bacteria. The scissors chop up DNA in specific ways, and enabled scientists to cut DNA in tailored ways. Opened up floodgates for genetic engineering.
Discovery of restriction enzymes 1970s
A breakthrough in our ability to detect tiny amounts of DNA and then amplify it into quantities sufficient for studying.
Polymerase Chain Reaction technique 1980s
The discovery that perhaps only 2% of DNA codes for a protein, so much RNA doesn’t end up with a protein counterpart–thus they have critical roles in regulating what happens in the cell.
The importance of small RNAs 2000s
The discovery that even though the exact types of microbes found in and on different people are highly diverse, the overall set of metabolic capabilities the bacterial communities possess is remarkably similar among people.
Genetic Identification of the Human Microbe 2010s and beyond
Formulate a question Do background research Construct hypothesis Test hypothesis Analyze data and reject or accept hypothesis Communicate results
Scientific Method
The discovery and detailed description of heat-resistant bacterial endospores was by
Ferdinand Cohn
First to introduce aseptic technique
English surgeon Joseph Lister
A theory originating in the 1800s that proposed that microorganisms can be the cause of diseases; so well established that it is considered a fact.
The Germ Theory of Disease
Bacterium that causes anthrax
Bacillus anthracis
Four main families of macromolecules
Lipids, nucleic acids, carbohydrates, proteins
All macromolecules are formed by polymerization, a process in which repeating subunits termed monomers are bound into chains of various lengths called ______.
polymers
Nucleic acids
Nitrogen base Purines
adenine (A) and guanine (G)
Nucleic acids
Nitrogen base Pyrimidines
thymine (T)
cytosine (C)
uracil (U)
Cell walls in plants and many microscopic algae derive their strength and rigidity from ______, a long, fibrous, polysaccharide.
Cellulose
A polysaccharide found in seaweed and commonly used to prepare SOLID culture media.
Agar
A network of polysaccharide chains cross-linked by short peptides that forms the rigid BACTERIAL cell walls.
Gram neg bacteria have smaller amounts of this rigid structure than gram pos
(think closed sandwich cell wall with gram pos)
Peptidoglycan
A molecular complex of lipid and carbos found in bacterial cell walls.
The portion of this complex in a gram neg bacteria is an ENDOTOXIN with generalized pathologic effects just as fever.
Lipopolysaccharide
A filamentous network or carbohydrate-rich molecules that coats cells.
Serves as a protective outer layer, and can also play a role in attachment of the cells to other cells or surfaces.
Glycocalyx
Water-loving region of a phospholipid in a membrane
hydrophilic
Water-fearing region of phospholipid in membrane.
Hydrophobic
Best known member of a group of lipids called steroids.
Commonly found in cell membranes and animal hormones.
Reinforces the structure of the cell membrane in animal cells and in mycoplasms (cell wall deficient unusual bacteria)
Cholesterol
Building blocks of proteins
amino acids
Initial protein organization described by type, number, and amino acids in the chain.
Primary Structure (of proteins)
A protein biocatalyst that facilitates metabolic reactions
enzyme
RNA that is a copy of a gene that provides the order and type of amino acids in a protein
Messenger RNA
Type of RNA that is a carrier that delivers the correct amino acids for protein assembly
transfer RNA (tRNA)
Type of RNA that is a major component of ribosomes
ribosomal RNA (rRNA)
A nucleotide that is the primary source of energy to cells.
Adenosine Triphosphate (ATP)
Animals, plants, fungi, and protozoa are all made up of ________ cells.
eukaryotic
The science of classifying living beings
Taxonomy
The assignment of scientific names to the various taxonomic categories and to individual organisms.
Nomenclature
Always a combination of the genus name followed by the species name.
Ex: Escherichia coli
Genus species
Binomial system of nomenclature
What is the genus of:
Staphylococcus aureus
Staphylococcus
Method of organizing organisms into several descending ranks, beginning with the most general all-inclusive taxonomic category and ending with the smallest most specific category.
Classification
What are the taxonomic categories from top to bottom
DKPCOFGS
Domain, kingdom, phylum, class, order, family, genus, species.
Compare humans to protozoa in terms of classification
Both nucleated cells (eukaryotes) so they are in the same domain: Eukarya.
But they are in different kingdoms b/c humans are multicellular (Kingdom Animalia) and protozoa are single-cellular organisms that, together with algae, belong to kingdom Protista
The scheme that represents the natural relatedness between groups of living things
Phylogeny
Classification tree description
The trunk of the tree represents the origin of ancestral lines
taxonomic groups with less divergence from the common ancestor closer to the root of the tree
taxa with lots of divergence closer to the top
Five Major Taxonomic Kingdoms
FAMPP: Fungi Animals Monera Protists Plants
Three Domain System
Bae:
Bacteria
Archaea
Eukaryotes
Sample is introduced into a container of growth medium to culture microorganisms.
Medium can be solid, liquid, or a live animal.
Inoculation
Body fluids (blood, cerebrospinal fluid, peritoneal fluid), discharges (sputum, urine, feces), anatomical sites (nose, throat, genital tract, ear, eye), or diseased tissue (such as an abscess or wound)
Other: soil, water, foods, air, sewage, other inanimate objects.
Clinical specimens
Once a container of medium has been inoculated, it is placed in a temperature-controlled chamber to encourage multiplication.
Incubation
A growth medium that contains one a single known species or type of microorganism.
Pure Culture
A container that holds two or more identified, easily differentiated species of microorganisms.
Mixed culture
Was once a pure or mixed (with known species) culture but has since has contaminants (unwanted microbes of uncertain identity introduced).
Contaminated culture
Three properties of media
- Physical state ie. liquid, soild, solid, semisolid
- Chemical composition ie. complex, defined
- Functional type ie. enriched, selective, assay
Water based solutions that do not solidify at temperatures above freezing.
Growth appears cloudy, or as flakes, or settle at the bottom of the vessel.
Liquid media
Firmer than liquid media but not as firm as solid media.
Do not flow freely, and have a soft, clot-like consistency at room temp.
Used to examine motility of bacteria and to provide a backdrop for visible reactions to occur.
Semisolid Media
Media containing 1%-5% agar are solid enough to remain in place when containers are tilted or inverted.
Can be liquified with heat.
Provide a firm surface on which cells can form discrete colonies.
Solid/Reversible to Liquid Media
What media is essential for the development of discrete, isolated colonies?
Solid media.
Once it is liquefied, agar does not resolidify until it cools to ____ degrees Celsius.
Agar has a boiling temp of ___ degrees Celsius.
42
100
Media whose compositions are precisely chemically defines are termed ______ or ______.
Defined or synthetic
Media whose compositions are not precisely chemically defined are termed ______.
This media can contain extracts of animals, plants, yeasts, ground up tissues or secretions, such as blood, serum, or meat extracts.
Complex
Three examples of complex media.
Nutrient broth
Blood agar
MacConkey agar
There are many more microbes that we ______ cultivate in the lab than those that we ____.
; Cannot
; Can
Media that will allow the growth of as broad a spectrum of microbes as possible.
Ex: brain-heart infusion, trypticase soy agar (TSA), and nutrient and agar broth
General-purpose media
Media that contains complex organic substances such as blood, serum, hemoglobin, or special growth factors (specific vitamins, amino acids) that CERTAIN species MUST have.
Bacteria that require these conditions are termed fastidious.
Enriched media
Bacteria requiring special nutritional or environmental conditions for growth
Fastidious
______media are also useful in the clinical laboratory to encourage growth of pathogens that may be present in very low numbers, such as in urine or blood specimens.
Enriched
Example of enriched media.
Chocolate agar
; blood agar with added hemin and nicotinamide adenine dinucleotide
Contains one or more agents that inhibit the growth of certain types of microbe(s).
Ex: Microbes A, B, C, D are inoculated, but the media inhibits all but microbe D to grow.
Selective Media
List three examples of selective media.
; dyes like methylene blue and crystal violet, as well as antimicrobial drugs can act as selective agents
- MacConkey Agar (contains bile salts as selective agent)
- Tomato juice again (contains tomato juice, acid for selective agent)
- Lowenstein-Jensen (contains Malachite green dye for selective agent)
Media that do not inhibit growth but display visible differences between microorganisms through variations in colony size/color, media color changes, or in formation of gas bubbles and precipitates.
Ex: Blood agar (intact red blood cells) Urea broth (urea, phenol red) Birdseed agar (seeds from thistle plant) Mannitol salt agar (mannitol, phenol red)
Differential media
A single medium can be both _________ and _________.
selective and differential