1. Scope of Microbial Life Flashcards
Define ‘microbiology’
the study of microscopic organisms e.g bacteria, fungi, archaea
Define ‘microorganism’
a microscopic organism
Microorganisms are measured in…
micrometres
Fungi are … to … micrometres
10-50
Protozoa are … to … micrometres
10-100
Viruses are … to … nanometres
50-200
Rank bacteria, fungi, protozoa and viruses from largest to smallest
fungi, protozoa, bacteria, viruses
3 subheadings of the tree of life
- bacteria
- archaea
- eukarya
List classifications of tree of life
- domain
- kingdom
- phylus
- class
- order
- family
- genus
- species
- strain
Protozoa and fungi are in which top taxonomic level?
eukarya
Microorganisms can be unicellular, multicellular or acellular. Define all 3
- single cell organism e.g bacteria, archaea, protozoa
- organism made of two or more cells e.g fungi
- not cells at all so not truly living e.g viruses and prions
How do microbial processes impact the environment?
- creation of the Earth’s atmosphere
- nitrogen cycling
- decomposition
- metal ore recovery
- sewage digestion
How do microbial processes link to disease?
can cause disease in man, animals and bacteria
How do microbial processes link to biotechnology?
- antibiotics
- therapeutics
- genetic engineering
- human gene therapy
What microbe is involved in bread?
saccharomyces cerevisiae
What microbe is involved in cheese?
lactic acid bacteria
What microbe is in Quorn?
fusarium venenatum
Define ‘commensalism’
- a close permanent relationship between two species of organisms
- in which one benefits and other remains unharmed and unaffected
Who discovered dental plaque?
Antoine van Leeuwenhoek
How many bacteria in human body?
2kg
Archaea were thought to be bacteria but diverged … years ago. They share features with … such as …
- 2.5 billion
- eukaryotes
- DNA replication initiated at multiple origins
Protozoa are single celled … found in … environments e.g …
They graze on …
Some examples of protozoa are …
- eukaryotes
- aquatic
- dental unit waterlines
- bacteria
- amoebae, plasmodium spp. (that causes malaria)
Give 3 oral protozoas
Which is the most dangerous?
- trichomonas tenax
- entamoeba gingivalis
- leishmania (only serious disease causing one in the oral env)
Fungi are … eukaryotes
Some form … structures e.g mushrooms or …
A transition between … and …
- simple
- multicellular
- pin moulds
- yeast and hyphal forms
Fungi have non/membrane bound organelles
Mitochondria?
Slow/fast growing?
- membrane bound
- mitochondria
- slow
Cell wall structure in fungi?
contains chitin - diff to most eukaryotes
A virus is in/capable of independent replication?
It is a … … parasite
A … acid in a … coat
- incapable
- obligate intracellular
- nucleic, protein
Viruses have a small/large genome
What range?
small
5-230 kb
How do prions cause disease?
- when a host-encoded alpha helical protein (PRPC)
- is converted to a beta-pleated sheet form (PRPSc)
… PRPSc trigger disease - further conversion of PRPC is …
- exogenous
- autocatalytic
What is the main example of an issue prions cause?
What happens to a person with this?
- transmissible spongiform encephalopathies
- loss of voluntary and autonomic function
- degeneration and death
What’s so dangerous about prions?
- PRPSc is extremely resistant to heat (inc. autoclaving) and proteases
- very difficult to kill so extreme care required to avoid iatrogenic transmission
What is iatrogenic transmission?
between patients by medic/dentist
How do microbial processes link to food/drink?
- bread
- cheese
- beer/wine
- vinegar
- yoghurt
