Lecture 1 Flashcads Flashcards
What is mircobiology?
It is the study of microorganisms which are living organisms that are too small to be seen with a naked eye such as bacteria,virus,yeast,fungi and archaea.
The techniques used for the visualisation identification and study of microbial function are in different varieties.
The science of microbiology was originated with intention of the microscope. Few bacteria are bigger then some eukaryotic cell.
Seeing is believing history of microscopy invention
1)zaccharias and Hans Jansen ( Dutch eyeglass makers) in about 1950 produced the first compound microscope
2) Robert Hooke (1635-1703) English scientist who improved the design and capability of the compound light microscope which observed insects sponges protozoans and more.
3) Anton van Leeuwenhoek known as father of microscopy observed protozoans and bacteria
Where is life coming from?
1)abiogenesis = spontaneous generatiiion
2)proponents=firmly believed that living things can come from no living matter(john needham: turbidity ini boiled broth)
3)opponents= started doubting and developed experiments to contradict abiogenesis
. Fransescio redi= maggots from fly eggs meat in different containers
.anton van Leeuwenhoek: animalcules gave fuel for each side of the debate
.Lazard spallanzani:repeated needhams experiment without air access to the flask
.Louis Pasteur:the definitive experiment with British in swan necked flasks
Louis Pasteur and the swan necked flasks
Image description
1) the broth was boiled to kill miscrobes the afire enters through the tube
2) after a year no microbes appeared as the microbes were trapped in curve
3) he flask was tipped to allow the broth to reach the microbes
4) microbes quickly multiplied in the flask
Germ theory of disease
Suspicion that microorganisms cause not only spoilage and decay but also infectious disease
1)childbirth deaths linked to dirty hands of physicis
2)linked maternity infections to contamination of hands required chlorine solution wash.
3)expanded protocols with aerosol disinfection introduced aseptic techniques
Microscopy
Light microscopes: use visible light and optical lenses either simple or compound ocular lens or objective lens.
Dissection and stereomicroscopes: Lowe power for observing whole objects has a bright field microscope and the background is lighter than the observed specimen. Most specimens require fixing and staining for bright field microscopy.
Dark field microscope:used to view unfixed,unstaffed specimens such as living organisms has a dark background and the specimen is bright.
Phase-contrast microscope: used to view unfixed and transparent specimens.effective for observation of cytoplasmic streaming,motility and the dynamics states of cell organelles.
Microscopy(fluorescence microscopes)
Ultraviolet illumination
Visualisation of specimens that contain natural fluorescent substances or that have been stained with fluorescent rains/dyes
Used in diagnosis iiof infectious diseases
Used in microbial eco log
Applied to identify specific antibodies in response to antigens
Microscopy(confocal miscorcopes)
Sharper images
Allows visualisation of different places of a specimen
Often buys using a lazier for illumination
Image can be displayed three dimensionally with electronic staining
Microscopy ( electron microscopy)
Transmission electron microscopy.
Electrion beam goes through specimen and magnetic field instead of the optical lenses. Special preparation,sectioning,and staining .
Creates two dimensional images
Good internal detail
Pictures are referred to as electron micrographs
Microscopy (electron microscopy)
Scanning electron microscopy SEM
No sections
Scans the surface of an object
Three dimensional image
Diversity of microbiology
Shapes s,sizes,arrangements ,staining,energy source,temperature,PH,pressure,oxygen requirements
Classification of microgoranisms
Fossil records show that the fist lviiiivng organisms ere prokaryotic 3.4-4 billliion years ago
From them all other organism evolved
Domains of life
How to distinguish different microorganisms?
1) phenotypic: how they look like there size shape and organisation and colour
2)analytic: their composition
3)genotypic:their genetic information such as rRNA
Classification of microorganisms
Prokaryotes(no membrane bound organelles such as nucleus) these are archaea and bacteria)
Eukaryotes ( microorganisms with membrane-bound cell organelles such as algae fungi and protozoans)
Taxonomy
The formal system of organising classifying and naming living organisms
Each organisms has a least two names which I are the genus and species. Scientific names are italiasized or underlined.
The Genus is capitalised and the species is in lower case.
After the first uses cieintific names may be abbreviated with the first letter of the genus for example.
Escherichia coli= E.Coli
