Lecture 17- Bacterial Classification & Morphology Flashcards
In what way did Avon Leeuwenhoek I rove the microscope and when did he first see microorganisms?
Made microscope clearer up to 200x, in 1675 he saw the microorganisms
What is taxonomy?
The identification and naming of organisms
How is the binomial naming system derived?
[Genus descriptive feature]= Species
What is panther leo Panthers onca Panthers pardus?
panther leo = Lion Panthers onca= jaguar Panthers pardus= leopard
How many original kingdoms were there (name them) and how many are there now?
2 (plants and animals) now 6
Is it true that the division between prokaryotes and Eukaryotes is based on Kingdom?
No, because while bacteria and Archaea are both prokaryotes, they are divided into 2 different domains.
instead the difference between prokaryotes and Eukaryotes is cell structure and organization
Prokaryotes: organisms without membrane bound organelles and nucleus
opposite for Eukaryotes
What is the typical range of length and width of prokaryotes?
- 1-10 μm length
- 0.7-1.5μm width
What are difference in characteristic between Bacteria and Archaea?
- Archaea do not have peptidoglycan cell wall
- Archaes have 3 types of RNA polymerase (R,T,M) while Bacteria 1
- the protein synthesis imitator in bacteria is f-Methionine , archaea Methionine
- growth is inhibited for bacteria in presence of Streptomycin (antibiotic) Archaea not
- DNA in bacteria is not associated with histones, Archaea it is
What is the characteristic differences between Archaea and Eukaryotes
- Archaea have no nuclear envelopes & membrane enclosed organelles Eukaryotes do
- Archaea chromosomes are circular while Eukaryotes linear
- Archaea 70S Eukaryotes 80S
What Is the practical use of classification?
identification (isolating and identifying disease causing agents)
What is the conventional classification scheme?
classification on visible phenotypic features (similarities and differences)
what are microbes grouped according to in molecular classification?
Evolutionary relatedness
What are some conventional features used to classify bacteria?
- Cell wall
- shape of bacteria
- Bacterial size
presence or absence of flagella - presence or absence of pili
- presence or absence of capsule
- ability to form spores
What are characteristics of gram-positive bacteria?
- have a thick peptidoglycan layer
- 1 membrane bilayer
- lower lipid content compared to -
What are some ways cocci (round bacteria) can arrange?
- pairs
- chains
- clusters
What are the ways that bacilli (rod) shaped bacteria can rearrange, and are all of them sport forming?
- regular/irregular
- No, some are spore forming, some are not
What are some unique features of gram - bacteria?
- have a thin peptidoglycan cell wall (sandwiched)
- 2 bilayers
- contain lipopolysaccharide on outer cell membrane
- Some are obligate intracellular parasites
- Rickettsia (have cell wall)
- Chlamydia (no cell wall)
