1st quarter microbiology 214 summary

Harmful micro-organisms that cause disease.

Antwoord: Pathogens

Acellular parasites that require host cells.

Antwoord: Viruses

Single-celled prokaryotes that contain peptidoglycan in their cell walls.

Antwoord: Bacteria

Extremophiles with distinct rRNA sequences and no peptidoglycan in their cell walls.

Antwoord: Archaea

Unicellular eukaryotes

Antwoord: Protists

Multi- or unicellular eukaryotes

Antwoord: Fungi

Give 3 similarities between archaea and eukaryotes.

Antwoord: Introns in genes, have a gene translation mechanism, no peptidoglycan in their cell walls.

Give 3 similarities between archaea, eukaryotes and bacteria.

Antwoord: Presence of DNA, membrane-bound cytoplasm, presence of ribsomes.

The theory that suggested organisms develop from non-living matter.

Antwoord: Spontaneous generation

Disproved the theory of spontaneous generation for large animals by showing that maggots on decaying meat came from fly eggs.

Antwoord: Franscesco Redi

Why is sampling important? (4)

Antwoord: Quality control, identification of potential industrial strains, disease diagnosis, answering fundamental research questions.

Why are standard operating procedures important when it comes to sampling?

Antwoord: Ensures samples are the same, so results are valid and accurate.

What is the advantage of using commercial sampling kits?

Antwoord: They are validated for certain uses and save time (however they are expensive).

What should be considered when analysis requires intact nucleic acids?

Antwoord: Environmental conditions, DNA/RNA contamination, presence of proteases.

What are the disadvantages of culture-dependent methods?

Antwoord: Unculturable microorganisms, labour intensive, time-consuming.

What are the advantages of culture-independent (molecular) methods?

Antwoord: No culturing required, quick, can be used to detect byproducts.

What are the disadvantages of culture-independent (molecular) methods?

Antwoord: Require special skills and complex extraction methods, expensive equipment.

What are the three methods of enumeration?

Antwoord: 1. Dilution series and plating to determine CFUs. 2. Gridded membrane filter. 3. Ten-fold dilution series to determine the most probable number.

What factors should be considered when choosing between culture-dependent and -independent methods?

Antwoord: Time available, cost, high- or low-throughput.

What is complex media?

Antwoord: Media with an UNKNOWN chemical composition, providing the nutritional growth requirements for MOST microorganisms.