Microbiology Flashcards
(24 cards)
What is a pathogen?
An organism or entity capable of causing diseases
Host definition.
An organism in which infected pathogens live on or in and multiply.
What is pathogenicity?
The ability of a pathogen to cause disease in a host by overcoming the host’s defenses.
Parasite definition.
An organism which lives in or on another living organism (host) and obtains nutrients and other resources from the host.
What is invasiveness?
The ability of pathogens to invade tissues by overcoming the host’s defense mechanisms and multiply for colonizing.
What is toxigenicity?
The ability of microbes to produce biochemical substances known as toxins that disrupt the normal functioning of cells.
Mineralization definition
The decomposition of plant and animal residue by extracellular enzymes of bacteria and fungi.
What are the significances of mineralization?
- Removes plant and animal debris from the earth, allowing other organisms to live.
- Recycles minerals found in limited quantities on Earth.
What is nitrification?
The process of oxidizing the nitrogen in the ammonium ion to produce nitrate.
What is Nitrogen fixation?
The process of conversion of nitrogen gas into ammonia.
What are the methods of reproduction of Bacteria?
Binary fission, fragmentation or budding.
Conjugation.
What are the methods of reproduction of Cyanobacteria?
Only asexual. Unicellular forms through normal cell division. Colonial forms through fragmentation.
How do fungi reproduce?
Asexually by fission or budding. Filamentous fungi reproduce asexually or sexually by producing spores.
What are the modes of nutrition of fungi?
Chemoheterotrophs. Can be saprophytic and absorptive heterotrophs. Can be mutualistics or parasites.
How do protists reproduce?
Sexually by the production of gametes, asexually by fission.
Consequences of using chemical pesticide instead of BCAs
residues will remain in food and environment, residual toxicity can harm non-target insects and resistance to the pesticide can be developed
Why do we use dyes to stain slides?
To highlight the entire microbe and to make cellular shapes, cell arrangements and basic structures MORE VISIBLE.
The main morphological symmetries in viruses
Icosahedron and helical
Main morphological forms in viruses
Helical, icosahedron or polyhedral, complex and enveloped.
Explain the helical and icosahedral forms of viruses
Helical - rigid or flexible rods, like Rabies virus
Icosahedral - icosahedral symmetry, like adenoviruses.
Explain the complex virus structure
Have more than 1 form of symmetry with additional structures, like Bacteriophages
What are enveloped viruses?
Roughly spherical viruses where the capsid is covered by an envelope. like Herpes simplex virus
How are microbes killed in moist heat sterilisation?
Through denaturation of proteins due to high temperature and pressure
Through what setup is hot air sterilisation done through?
Dry air ovens.
