Microbiology in General Flashcards
Define microbiology?
It is defined as the study of organisms too small to be seen with the naked eye.
Give examples of organisms that are too small to be seen with the naked eye?
Viruses Bacteria Algae Fungi Protozoa
What are microbes?
Microbes are products of evolution, consequence of natural selection operating upon vast array of generally diverse organisms.
Who was the first person to advocate handwashing?
Ignas Semmelweis.
Note: In 1840’s, he advocated handwashing to prevent transmission of puerperal fever from one person to another.
Who was the first person that introduced the antiseptic system?
Joseph Lister
Note: In 1860’s , he used it to prevent surgical wound infections.
Who invented the process of pasteurization and discovered that micro-organisms causes fermentation and diseases?
Louis Pasteur
Who was the person that discovered the bacteria that caused anthrax, septicaemia, tuberculosis and cholera?
Dr Robert Koch
Who discovered penicillin?
Alexander Fleming
Which microbe is acellular(not composed of cells)?
Viruses
What are the types of micro-organisms?
Archaea
Bacteria
Eukarya
Which microbes are prokaryotes?
Bacteria and Archaea
Which microbes are eucaryotes?
Protists
Fungi
Plants
Animals
What is the major characteristic that distinguish prokaryotes and eukaryotes?
The cell of prokaryotes lack nucleus whereas the cells of eukaryotes contain nucleus.
What is a pathogen?
It is an organism that causes disease.
The cell walls of bacteria contain _____________.
peptidoglycan
What are the common shapes of bacteria?
- Spherical(Coccus)
- Rod-shaped(bacillus)
- Curved(Spirillum, spirochette or vibrio)
What are photosynthetic bacteria?
These bacteria use energy derived from sunlight and fix carbon dioxide for growth.
Give examples of photosynthetic bacteria?
- Oxygenic cyanobacteria
- Anoxygenic green sulphur
- Green non-sulphur bacteria
What are non-photosynthetic bacteria?
These bacteria obtain their energy from organic or inorganic compounds in their environment.
The cell wall of archaea contain _______________.
pseudopeptidoglycan
Algae falls into which category of eukaryotes?
Protists(plant-like)
The cell wall of algae cells are made up of ________ , a type of ____________ .
cellulose; carbohydrate
Algae are _____________ organisms that extract energy from the sun and release oxygen and carbohydrates into their environment.
photosynthetic
Which gel is derived from algae?
Agar
List some differences between prokaryotic cells and eukaryotic cells?
- PCs are very minute in size whereas ECs are fairly large in size.
- PCs have only a single chromosome whereas ECs have more than one chromosome present.
- Nucleolus absent in PCs whereas nucleolus present in ECs.
- Membrane bound organelles are absent in PCs whereas they are present in ECs.
- Cell division in PCs occurs by fission or budding(no mitosis) whereas cell division in ECs occurs by mitosis or meiosis.
What are gram-positive bacteria?
They are bacteria with thick cell walls that yield a positive result during a gram stain testing. (The bacterium’s cell wall stained purple)
What are gram-negative bacteria?
They are bacteria that does not yield a positive result during gram stain testing resulting in a pink stain.
What are the characteristics of gram-positive bacteria?
- No outer membrane
- Complex cell wall
- Thick peptidoglycan layer
- Certain surface appendages
What are the characteristics of gram-negative bacteria?
- Outer lipid membrane
- Thin peptidoglycan layer
- Usually doesn’t have teichoic acids
- Can have flagella or pili
Give some examples of gram-positive bacteria?
Staphylococcus
Streptococcus
Bacillus
Clostridia bacteria
Give some examples of gram-negative bacteria?
E.coli
Salmonella
Shigella
What are helminths?
They are multicellular parasitic worms.
Note: They are not technically micro-organisms as most are large enough to be seen without a microscope.
Why does helminths fall within the field of microbiology?
Because diseases caused by helminths involves microscopic eggs and larvae.
Give an example of a helminth?
Guinea worm(Dracunculus Medinensis)
When does an infection involving helminths typically occurs?
After a person drinks water containing water fleas infected by guinea-worm larvae.
Define mycology?
It is the study of fungi.
What are fungi?
They are a group of eukaryotic organisms with a diversity of morphological appearances depending on species.(Mostly molds and yeasts)
What are mycoses?
They are fungal infection.
Fungi are _______________ and their cell walls are usually made out of ________ rather than cellulose.
non-photosynthetic; chitin
What is the use of molds in the pharmaceutical industry?
To make penicillin and cyclosporine.
List some importance of fungi?
- Nutrition(Edible mushrooms)
- Industrial use
- Fermentation(Brewer’s and Baker’s yeast )
- Plant pathology
- Medical importance
Fungi are ____________ and can be unicellular or __________ .
eukaryotes; multicellular
Fungi are said to be heterotrophic, which means?
They use a wide variety of materials for nutrition.
What are the components that make up fungi cell wall?
- Chitin
- Glucans
- Mannans
- Complex polysaccharides