Week 1 Flashcards
What is an example of an archaea extremophile?
Thiomargarita namibienisis - found in the ocean, unharmful
What archaea are adapted to high temperature?
Thermophile
Membrane is adapted to remain fluid at increased temperature,
Enzyme structure adaptation to prevent denaturing,
Proteins fold different to withstand extreme temperatures
What biotechnical application can extremophiles be used for?
- PCR
- Biofuels
- Biomining
- Carotenoid production (uses halophiles)
- Detergents
What thermophile can be used during polymerase chain reaction?
Thermus aquaticus
(Used as a heat resistant enzyme, Taq DNA polymerase)
Components of prokaryotic cells?
Pili
Nucleoid
Ribosomes
Plasma Membrane
Cell Wall
Capsule
Flagella
Cytoplasm
(Classified by shape)
Prokaryotic cell components: Nucleoid
Contains circular DNA, no nuclear membrane
What are the most common shape of bacteria?
Cocci
Bacilli
Spirochetes
Prokaryotic cell components: Plasma membrane
Has the same basic structure of all biological membranes
Some prokaryotes have infoldings of the plasma membrane which contain specialised enzymes that perform specific functions (eg cyanobacteria have thylakoids)
How does the flagella allow for movement?
Movement by a rotatory motor
Oxidises ATP by pumping H+ out of the cell, generating a gradient, diffusion of these H+ back into the cell, turs the Hook which causes filament to turn and propel
What are autotrophs
(Modes of nutrition)
Producers - make own food - pants, algae, bacteria
What are heterotrophs?
Modes of nutrition)
Consumers - consume producers/consumers - mammals
What is photo?
Modes of nutrition)
Use light
What is chemo?
Modes of nutrition)
Use molecules/compounds
What are Eukaryotes: modes of nutrition?
Photoautotrophs and chemoheterotrophs
What are prokaryotes: mode of nutrition?
Chemoautotrophs, chemoheterotrophs, photoautotrophs and photoheterotrophs
Examples of extremophiles, adapted to pH
Hyperacidophile
Acidophile
Neutrophile
Alkaliphile
Hyperalkaliphile
Examples of extremophiles, adapted to temperature
Psychrophile
Mesophile
Thermophile
Hyperthermophile
Examples of extremophiles, adapted to salinity (salt)
Non-halophile
Halotolerant
Halophile
Extreme halophile
Examples of extremophiles, adapted to pressure
Barotolerant
Barophile
Hyperbarophile
Examples of extremophiles, adapted to water activity
Xerophile
What is a polyextremophile
An archaea/extremophile with tolerance or preference to multiple parameters combined
Prokaryotic cell components: Cytoplasm
Contains ribosomes and little else
Prokaryotic cell components: Flagella
Some prokaryotes have flagella which is composed of the protein flagellin
Prokaryotic cell components: Pili
Composed of the protein Pilin and help bacterial stick to their substrate or to each other.
They extend to attach onto other bacteria and stick together bacteria and conjugate, sharing genetic material
Prokaryotic cell components: Capsule
Many bacteria have this, and is usually composed of polysaccharides
What is the function of the prokaryotic cell wall?
Protects cell against mechanical and osmotic shocks
Composed of the molecule peptidoglycan
Can be divided up into two types: Gram+ and Gram-
Features of gram+ cell wall?
Peptidoglycan = thick (20-80nm)
Cell wall structure = Simple, single layer
Teichoic acids = present
Lipopolysaccharide = Absent
Gram stain = Purple
Antibiotic resistance = susceptible
Features of a gram- cell wall?
Peptidoglycan = thin (<10nm)
Cell wall structure = Complex, double layer
Teichoic acids = absent
Lipopolysaccharide = present
Gram stain = Pink
Antibiotic resistance = resistant
Example of gram+ bacteria?
Clostridium tetani (tetanus)
Clostridium botulinum (botulism)
Streptococcus pneumoniae (pnumonia)
Example of gram- bacteria
Chlamydia trachomatis (common cause of infectious blindness)
Vibro cholerae (cholera)
Yersinia pestis (plague - ‘black death’)
Medical Advantage of Bacteria in biotechnology
Bacteria can be used to produce large quantities of proteins cheaply for therapeutic use, eg insulin
Drug screening tests and diagnotics
Agricultural Advantage of Bacteria in biotechnology
Introduction of a new gene in plant chromosome
Eg purple tomatoes have high anthocyanin
Environmental Advantage of Bacteria in biotechnology
Bioremediation - removes pollutants, industrial by-products, oil spills
Industrial Advantage of Bacteria in biotechnology
Lactic bacteria develop the flavour and colour of foodstuff
Improve the storage longevity of wines
Photoautotroph major nutritional modes
Energy source: Light
Carbon source: CO2, HCO3- or related compound
Types of organisms: Photosynthetic prokaryotes (eg cyanobacteria, plants, certain protists)
Chemoautotroph major nutritional modes
Energy source: Inorganic chemicals (eg H2S, NH3 or Fe2+)
Carbon source: CO2, HCO3- or related compound
Types of organisms: Unique to certain prokaryotes (eg Sulfolobus)
Photoheterotroph major nutritional mode
Energy source: Light
Carbon source: organic compounds
Types of organisms: unique to certain aquatic and halophile prokaryotes (eg Rhodobacter, Chloroflexus)
Chemoheterotroph major nutritional modes
Energy source: Organic compounds
Carbon source: Organic compounds
Types of organisms: many prokaryotes (eg Clostridium) and protists; fungi; animals; some plants
Features of a filamentous virus?
Nucleic acid is arranged in a helix, with the protein sub-units surrounding and stabilizing it.
Eg Tobacco mosaic virus
Features of a Spheroid virus?
Nucleic acid is considered inside a protein envelope which is usually organised into a multisided geometric shape
Eg adenovirus - different types cause illness ranging from Gastroenteritis to Keratoconjunctivitis
Features of an enveloped virus?
Have lipid envelopes
Including influenza and coronavirus
Features of a Tailed spheroid virus?
Basically a spheroid virus with a tail
eg the lambda phage
When was the light microscope invented?
17th century, allowing individual cells to be visualised
when was the electron microscope developed?
20th century, allowing cell organelles and molecules to be visualised and studies
What cells does the SARS CoV2 virus affect?
Induces the dedifferentiation of multiciliated cells and impairs mucociliary clearance
Who is the father of microscopy
Robert Hooke
1665 Robert Hooke published what?
A collection of essays under the title Micrographica.
One gave detailed description of a section of cork, in which Hooke described seeing honeycomb of chambers - called cells.
1675 Dutchman Anton Van Leewenhoekk improved what?
Art of polishing lenses.
His best microscopes were able to resolve to about 1.5 microns - he was able to report what he described as a host of little animals in a drop of rain water, (protozoa) and was later on described the existence of bacteria
What happened in the 19th century? (microscopy)
Maximum theoretical resolution of the light microscope was attained (about 0.25 microns)
In 1930s, electron microscope was developed allowing cell organelles to be seen. Ultrastructure was coined to describe the level of detail obtainable with the EM.
Define magnification
The ratio of an object’s image size to its real size
Define resolution
The measure of the minimum distance of two distinguishable points
(the closest two points can be, and still be resolved as being separate.)
Define contract in terms of microscopy
Visible differences in brightness or colour between parts of the sample
What are the types of light microscopes?
Dissecting (view surface features, 70x mag)
Compound brightfield (View indepth features, 400-1000x mag) (most common)
Others include: florescent, phase/differential contrast and confocal microscopes
Features of the light microscope? (top to bottom)
Ocular lens (eyepeice)
Focal plane of objective lens
Reflective prism
Objective lenses
Specimen on stage
Condenser lenses
Base with light source
Lamp field stop
What is the major advantage and disadvantage of the light microscope?
+ = Ability to image living things
- = Limited resolution eg best resolution is 0.2 microns. (Only way to improve this, is to use a shorter wavelength of radiation)
Whole mounts?
(Light microscope sample prep)
Small relatively transparent specimens mounted directly onto slides