week 1 Flashcards
acellular
viroids
viruses (protein coating)
prions
(need something else to replicate)
cellular
- prokaryotes
a. archaea
b. bacteria - eukaryotes
a. algae
b. protozoa
c. fungi
what is a cell?
- all cells have a cytoplasmic membrane, genome made of DNA, ribosomes, cytoplasm
- metabolism
- growth
- evolution
cell shapes
coccus, rods, spirillium, spirochete, budding, filamentous
uniceullar vs. multicellular
performs all of life functions for itself
multicellular = cells that depend on others for survival
endosymbiotic theory
mitochondria and chloroplasts originated as endosymbiots
evidence:
own DNA/ribosomes that is similar to bacteria
replicate independently of other cellular processes
RNA world theory
- self replicating RNA + liposomes = prehistoric cells
- these develop into DNA containing bacteria
3, archeoeukarya arise - some develop endosymbiotic relationship with mitochondria = seperation of archaea and eukarya
Louis pastuer
disproved spontaneous generation with his flasks that let air in but trapped microorganisms so they couldnt get to sterile liquid - nothing grew
Koch postulates
established a causal link between the organism and the disease
- The microorganism must be found in abundance in all organisms suffering from the disease but should not be found in healthy organisms.
- The microorganism must be isolated from a diseased organism and grown in pure culture.
- The cultured microorganism should cause disease when introduced into a healthy organism.
- the suspected pathogen must be re isolated and shown to be the same as the original
how do we get phylogenies ?
16S rRNA DNA sequence
limit for resolution of light microscopes?
0.2 um
bright field microscopy
move in and out of fields of view with fluid dynamics
- can use stains to increase contrast
phase contrast microscopy
cells are alive
can view motility
fluorescence microscopy
certain molecules get excited when they absorb photons
- move to a higher energy state
- when they relax they emit a photon
- photon is a fluorescence
confocal fluorescence microscopy
gives 3D fluorescence