Lecture 1 - Morphology and Ultrastructure Flashcards
What constitutes a species (5 things)
- Mating constraints (classical)
- Visible characteristics (Gram, shape, spores)
- Metabolism
- Surface structures
- Molecular Relatedness
Biochemical tests can assess relatedness only if…
the cell is metabolically active
Five tools for assessing relatedness
- Biochemical tests
- Numerical taxonomy
- DNA optical mapping (restriction digest)
- Serotyping
- Direct gene sequence comparisons
Optical map assembly involves _____ DNA molecules on a glass chip
linearized
Serotyping (strain typing) involves what 4 characteristics?
- Antigens
- Antobiotic/phage sensitivity profiles
- Toxin production
- surface molecules
6 important bacterial phyla
- Proteobacteria (a, ß, g, Σ)
- Chlamydiae
- Bacteroidetes
- Actinobacteriae (Myco, coryne, Actinomyces)
- Spirochaetae (Trep, Lepto, Borrelia)
- Firmicutes
Mycoplasma cell shape
pleiomorphic (and small)
Mycoplasma energetics/metabolism?
What does its membrane require
Obligate intracellular parasites
Cholesterol
Mycoplasma does not contain a _____, only a ________.
No cell wall
only a membrane
Various archaea shapes
cocci, rod, spiral, others
Two types of energetics found in archaea
Lithotrophs, heterotrophs
Three energetic properties of archaea
- many extremophiles
- some produce methane
- protein synthesis resembles eukaryotes
Archaea envelope – it does not have ______ but has a ________
No peptoglycan *
Has a cell wall
**pseudo-pg, polysacch, protein
Major difference in archaea lipids
Ethers (Other life has esters)
The lipids also have** Branched Isoprene chains**
(instead of unbranched fatty acids)
Prokaryotes reproduce via ____. They have a _______ chromosome usually.
binary fission
Single circular chromosome
Cytoplasm of prokaryotes contains….
membrane invaginations
Specific membrane structures of prokaryotes
Mesosomes
Phycobilisomes, chromatophores
Cytoplasm of prokaryotes contains what?
Inclusion bodies (insoluble polymers, poly beta-OH butyrate, starch, glycogen, sulfur, polyphosphate granules)
Somal bodies (protein-bound vesicles, gas vesicles, magnetosomes (membrane-bound), carboxysomes)
Bacterial chromosome is…. (three properties
- anchored to membrane
- highly folded (not histones)
- few thousand genes
Important functional sites in bacterial cytoplasm
Enzymatic reaction centers
(reaction centers depend on DNA, mRNA and protein localization)