Ch.1-2 Flashcards
What is biotechnology?
Industry producing large quantity of microbes to solve biological problems. i.e. antibiotics, degradation of sewage etc.
Name the 5 medically relevant organisms collectively called microbes:
bacteria, fungi, parasites, prions, viruses
Who made the 1st microscope? What is this person called the “father of”?
Antonie Van Leeuwenhoek
Father of bacteriology
Father of protozoology
What are animalcules?
Tiny animals
Who performed the worlds first vaccination? What did he vaccinate against? Approx. what year?
Edward Jenner
Smallpox
1790
What are Dr. Ignaz Semmelweis & Sir Joseph Lister famous for?
Promoting hand washing and antiseptic treatment during child delivery and surgery, having a remarkable decline in infection and death.
Who is Louis Pasteur?
Father of microbiology
Created vaccines for anthrax and rabies
Disproved the theory of spontaneous generation?
What is the theory of spontaneous generation?
The idea that life can come from non-living things
Disproved by Louis Pasteur
What are the Koch Postulates?
Set of 4 criteria (developed by Robert Koch in the 1870’s) to establish that an organism is the cause of a disease.
- Show that an organism is present in animals infected with a given disease and not present in organisms not infected with that given disease.
- Obtain a pure culture of the organism and grow it in the laboratory.
- Produce the same symptoms seen in the infected animals by inoculating healthy animals with this isolate.
- Isolate the identical microbe from the newly infected animal.
What is “agar”?
Gelatin like solidifying agent used in laboratory culture media.
What is the 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.
What is Alexander Fleming known for?
Discovering agents that destroy bacteria.
1st, the enzyme lysozyme
2nd, penicillin
What is taxonomy?
The science of naming and classifying microbes (and other living things).
What are the 7 levels of organism “taxa” (classification)?
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What does the binomial naming system always include?
Genus & Species
Name the 5 kingdoms:
Who developed the 5 kingdoms?
Animalia Plantae Fungi Monera (Bacteria) Prostista
Developed by Robert Whitaker - 1969
What does biovar mean?
What does serovar mean?
Both are strain variations:
Biological variant Serological variant (immunologic variant)
What does prokaryote mean and what does it refer to?
What does eukaryote mean and refer to?
Pro=before
Kary=nucleus
Refers to cells with no nucleus (bacteria) as they have no nucleus
Eu=true
Kary=nucleus
Cells with a nucleus - basically everything except bacteria.
What are the 2 domains of bacteria? (higher level than kingdom)
- Archaea
2. Bacteria
What are organisms called when they have small differences, but are still in the same genus and species?
Strains
Approximately how large is an average bacteria?
How many microns in a millimeter?
1-4 microns
1000 microns in a millimeter
What is the most widely used stain used in microbiology?
Describe it?
Gram stain
Gram stain uses 2 different colors which differentiate gram negative and gram positive bacteria.
Hence, it is called a “differential stain”
Name and describe the 2 types of electron microscopy.
- Transmission Electron Microscopy (TEM)
Electrons pass through the specimen - good for viewing the internal structures of any specimen. Resolves to approximately 0.002 microns - Scanning Electron Microscopy (SEM)
Scattered electrons are detected - good for viewing the surface structures. Resolves to approximately 0.02 microns
What is a medium?
A nutritious extract or mixture of materials that will support microbe growth.
What is the most common laboratory medium used today?
(TSA) tryptic soy agar
Or
(TSB) tryptic soy broth
Explain the difference between polar and non-polar.
Polar molecules (such as water) have a positive and negative side or "pole" such as water, or a magnet. Non-polar has no charge (oil, lipids)
Most cell walls are made of non-polar lipids keeping most polar molecules out.
Name 4 macromolecules:
- Proteins: composed of amino acids joined by peptide bonds
- Polysaccharides: sugars polymerized into long chains (complex carbs)
- Nucleic Acids
- Lipids
What are the 2 sub-types of Nucleic acids?
DNA - deoxyribonucleic acid: the genetic material of all living cells
RNA - ribonucleic acid: involved in the expression of our genes
Define a gene.
A defined region of DNA that encodes a protein or RNA with a function in the cell.
Define a chromosome.
A single piece of double stranded DNA - typically has thousands of genes.
What is the structural difference between DNA and RNA?
DNA is double stranded
RNA is single stranded
Regarding cell morphology, describe the following terms: Coccus Bacillus Spirochete Vibrio
Coccus: spherical cell
Bacillus: rod shaped cell
Spirochete: helical cell
Vibrio: short spirochetes
Define the following terms in regards to cells: Mono Diplo Tetra Strepto Staphylo
Mono - single cell
Diplo - 2 linked cells
Tetra - 4 linked cells in a square formation
Strepto - chains of cells
Staphylo - clusters of cells (like clusters of grapes)
Since bacteria have no nucleus, where is the DNA located?
Free floating in the cytoplasm.
What is a “plasmid”
A small piece of DNA, usually only carrying a few genes.
What are ribosomes?
A cell organelle, ribosomes are an enzyme that performs DNA translation.
Describe a common difference between the cell wall of eukaryotic cells and bacterial cells.
A eukaryotic outer cell wall is typically called the “cytoplasmic membrane”, and is made of lipids. Bacteria typically have an additional outer layer or “cell wall” made from peptidoglycan (cellulose type material). It helps prevent lysis if the cell is to become damaged.
- *additionally, bacteria sometimes contain a 3rd membrane that is very porous and sometimes a very outer “capsule” sometimes called a “glycocalyx”.
- *bacteria vary greatly in how many layers they have and are collectively called the “cell envelope”
There are 3 parts of a bacterial flagellum. Name the 3 parts based on the description below:
- The anchoring part within the cell wall
- The pivoting part that connects to the anchor
- The long helical part
- Basal body
- Hook
- Filament
What is chemotaxis?
When the bacterium is moving toward or away from chemicals (moving in a chemical gradient)
- positive chemotaxis - attracted to a chemical
- negative chemotaxis - repulsion to a chemical
Some bacteria have smaller, hairlike appendages (independent of flagella). Name the 2 types.
Which is longer and more rigid?
Which is typically more numerous?
Pili & Fimbriae
Longer, more rigid: Pili
More numerous: Fimbriae
Where would you find “peptidoglycan” and describe it’s structure.
Peptidoglycan could be found in the cell wall of bacteria, around the cytoplasmic membrane. It is made of a polysaccharide called glycan forming a fishnet type structure, adding strength to the cell wall.
Name 2 biologically active items that destroy the bacterial cell wall.
Penicillin
Lysozyme
What structural component is unique to gram negative bacteria?
An additional (3rd layer) outer membrane
What chemical is unique to the outer membrane of gram negative bacteria?
Lipopolysaccharide
Describe the difference between the peptidoglycan layer of gram negative and gram positive bacteria.
Gram negative - single or very few layers of peptidoglycan
Gram positive - many layers
List the 4 steps of gram staining.
- Primary stain - crystal violet
- Grams iodine to “fix” the crystal violet so it aggregates
- Wash aggregates with acetone alcohol
- Counter stain with safranin so gram negative bacteria are identifiable
Why do some bacteria harbor “inclusions” or “granules”?
What are they composed of?
They provide an energy source
Polysaccharides or polyphosphates
What are the most environmentally stable of all known life forms? What “genera” produce them?
Spores
Genera producing spores include gram positive Clostridium and Baccilus.
List the primary function of the 3 bacterial appendages:
- Flagella
- Pili
- Fimbriae
- Flagella - motility
- Pili - gene transfer
- Fimbriae - attachment
What is phototaxis?
Positive phototaxis - attraction to light
Negative phototaxis - repulsion to light
Define “trichous”
Hair or hair like part
Gram negative bacteria have an additional membrane that gram positive bacteria do not. What is this 3rd layer composed of?
LPS
lipopolysaccharide
Gram negative bacteria have an additional membrane that gram positive bacteria do not. What is this 3rd layer composed of?
LPS
lipopolysaccharide
