biology of the microbial cell Flashcards
what is not an example used to explain spontaneous generation
fungal spores deposited on a piece of melon gives rise same type of fungi
what is the theory of spontaneous generations and how was it proved wrong
-life can arise from nonliving matter
-open container= formation of maggots in meat
-corked sealed container= no formation of maggots in meat
-gauze covered container= no formation of maggots in meat
theory of spontaneous generation: pasture
-life only comes form life
-used neck flask
-open to lifeforce but prevents microbe entry
-curve of neck prevents outside air form entering=no contamination
-when neck broke off bacteria reaches sterile broth and growth occurs
-people didnt belive this theory because people were inconsistant with boiling broth
person behind the origin of cell theory
-robert hooke observed and coined the term cells
cell theory
-living organism are made up of 1 or more cells
-cells are the fundamental component of life
-cells arise from pre-existing cells (i.e. cell division)
-activity of and organism depends on the total activity of the cells
-energy flow occurs within cells
-cells contain DNA and RNA (and cells evolve)
-cells of similar species have simular chemical components
endosymbiotic theory
-infoldings in the plasma membrane of an ancestral cell gave rise to endomembrane components, including nucleous and er
-in first endosymbiotic event, the ancestral eukaryote consumed aerobic bacteria that evolved to mitochondria
-the second endosymbiotic event the early eukaryote consumed photosynthetic bacteria that evolved into chloroplast
what is a prokaryotic cell
-includes bacteria and archaea
-do not have a nucleus enclosed in nuclear envolope
what do prokaryotes have instead of nucleus
nucleoid
coccus
round
bacillus
rod
vibrio
curved rod
coccobacillus
short rod
spirillium
spiral
spirochete
long, loose, helical spiral
diplo…
pair of two
tetrad
group of 4 cells arranged into square
strepto…
chain of cells
staphylo…
cluster of cells
typical size of bacteria
1-10 microns
typical size of eukaryotic cells
10-100 microns
are all bacteria small
no there has been one the size of eyelashes (not all are microscopic)
when using a bright field microscope what feature would differentiate a bacteria form a euakrya
mem bound nucleus + organelles, size
instead of membrane for organelles what do prokaryotes have
-inclusions and compartments
-which are for;
-energy storage
-gas vesicles: float in water
-magnetosomes: which are gas bubbles in cells that accumulate Fe so can sense magnetic field
endospores
-resistant to extreme temps and radiation
-do not absorb gram stain, only special endospore stains
-dehydrates; no metabolic activity
-dormant; no growth or metabolic activity
how does bacteria make endospores
-DNA replicates (asymmetric division)
-membranes form around the DNA (engulfment)
-forespore forms additional membrane (maturation)
-protective cortex forms around spore (maturation)
-protein coat forms around the cortex (mother cell lysis)
-spore is released
-germination
-binary fission
at which step can you inhibit spore formation
at the asymmetrical division
what is a eukaryotic cell
-membrane-enclosed nucleus
-membrane-bound organelles
you have isolated a new eukaryotic microbe you analyze its ribosomes and observe two different ribosomes a 70s and a 80s what is the best explination
the endosymbiotic theory: mitochondria and chloroplast arise from bacteria
