Intro to Microbiology #1 Flashcards
List org that cause infectious diseases
- Parasites: Helminths + Protozoa
- Fungi
- Bacteria
- Viruses
- Prions (controversial)
How do groups of microbes differ from each other?
- structure + mol make-up
- biochem + met strategies to obtain energy + nutrients
- rep processes to multiply
Which microbes are cells + not cells?
- cells:
- bacteria
- fungi
- protozoa + helminths
- not cells:
- viruses
Compare nucleic acids of microbes
- DNA + RNA
- bacteria
- fungi
- protozoa + helminths
- DNA/RNA - never both
- viruses
Compare type of nucleus of microbes
- eukaryotic:
- fungi
- protozoa + helminths
- prokaryotic:
- bacteria
- none:
- viruses
Compare rib of microbes
- 80S:
- fungi
- protozoa + helminths
- 70S:
- bacteria
- none:
- viruses
Compare mem-bound org of microbes
- none:
- bacteria
- viruses
- do have:
- fungi
- protozoa + helminths
Compare nature of outer surface of microbes
- virus: protein capsid, +ve/-ve lipoprotein envelope
- bacteria: rigid cell wall containing peptidoglycan
- protozoa + helminths: flexible mem
- fungi: rigid cell wall containing chitin
Compare method of rep of microbes
- viruses: require host cell machinery
- bacteria: binary fission
- fungi: budding/mitosis
- protozoa + helminths: mitosis
Which microbes are microparasites?
- viruses
- bacteria
- protozoa
- fungi
Which microbes are macroparasites?
helminths
Compare size of macro + microparasites
- big (naked eye)
- small (microscope)
Compare rep products of macro + microparasites
- macro: outside host (eggs/larvae) which then leave host + level of infection determined by no. of org that can enter host
- micro: within host (multiply to prod v. large no.s of progeny which cause overwhelming infection)
What microbes do hosts usually dev immunity to?
micro but not macroparasites
Why is line between macro + microparasites not always clear?
progeny of some macro remains within host + infection can lead to large no. of org
What is taxonomy?
science concerned with systematic classification of org + focus on precise identification of unknown agent
What is taxa?
Div of org into related groups based on sim characteristics
How are microbes named?
- All microbes except viruses are named according to genus + species (Linnean system)
- viruses have single name
List morphological characteristics used to classify bacteria
- nature of cell wall
- staining (gram stain - +ve/-ve)
- shape (cocci, bacilli/rods + spirilla/spirochetes)
- spore-forming abilities
Describe shape of diff bacteria
- cocci - spherical
- bacilli/rods - straight
- spirilla/spirochetes - long + helical
- some bacilli + occi form colonies + adhere end to end after they’re div, forming chains
Describe spore-forming abilities of bacteria
- some bacterial colonies change into stock structures, grow long branch filaments/form erect structures that release spores
How are bacteria classified according to met?
- bacterial growth affected by O2 depending on energy-gen system e.g. obligate microbes, facultative anaerobes + obligate anaerobes
What biochem properties can classify bacteria?
- prod of specific enz e.g. coagulase/toxins
Which characteristic has been used to classify bacteria more recently?
- ## DNA seq of their genome - recognition + characterisation of pathogens that can be grown in vitro + determining evo of microorg by comparing genome of diff species
