lec 2 Flashcards
name the 3 domains of al microorganisms
bacteria, archaea, eukarya
how did eukarya got evolved
bacteria and archaea had the same ancestors, then they evolved and divided into the current domains of microorganism. Then archaea evolved into eukarya
prokaryotes
bacteria and archaea
agar plate
solid media which micro-organism grow on.
in an agar plate the —- increases over time and it may eventually generate a —–
biomass, colony
name the properties of all cells
1) metabolism
2) growth
3) evolution
1: metabolism
all cells can take up nutrients and modify them into building blocks or generate nrg. i.e. cell wall components
the resulting functions carried by the cell are:
1) genetic: replication, transcription, translation
2) catalytic: nrg, biosynthesis
2: growth
when the biomass is favourable, nutrients consumed by the cells are converted into new cell materials in order to create daughter cells
3: evolution
- key characteristic of life
- cells do this in order to acquire new traits or skills
- sometimes they may specialize
impacts of specialization
- cells might lose genes that t eh don’t need
- as a result they waste less nrg on unwanted sources
—– capture evolutionary relationships
phylogenic trees
name the properties of some cells
1) differentiation
2) communication
3) genetic exchange
4) motility
differentiation
e. g. some cells can differentiate into spores
- capacity to perform specific set of functions
communication
cells communicate via chemical messages
genetic exchange
cells can inset their DNA into the recipient cell
microbial cells exchange DNA via ——
horizontal gene transfer (reproduction)
motility
swim and crawl
what is a cell
a cell is a closed compartment that is constantly doing chemical reactions to make more of its constituents and make another cell
organize the following based on increasing in size:
virus, polio, vacuole
polio –> virus –> vacuole
what is the limit in cell size
0.5 micrometer - 750 micrometer
animal cell size
10 micrometer wide
the — of the cell affects the size
shape
surface volume ratio
as volume increases, there is less surface available
why is the cell size a limited number
because the surface can handle a certain amount of volume in order to transfer nutrients and other compounds
to feed the whole volume, surface must be —- bigger
x2
what is the cue for the cell to divide
just before the cell reaches the upper limit, it divides into 2 cells
bacterial shapes
spherical,rod
nucleoid
rough region with no physical barriers
- prokaryotes store their DNA in this region
functions of the cell membrane
1) permeability barrier
2) protein anchor
3) energy conservation
cell membrane – permeability barrier
- prevents form leakage
- functions as a gateway: controls what enters and washes out
cell membrane – protein anchor
- site of many proteins that participate in transport, bioenergetics and chemotaxis
- sensors, adhesins, tranposerters, enzymes
the cell is — % protein and. —-% phospholipid
50, 50
cell membrane – nrg conservation
since the membrane is impermeable to charged molecules, a membrane potential is created
- the membrane potential forces the passage of ions, therefore pmf is generated
typical phospholipid found in bacteria
phosphatidylehtanolamine
in bacteria and eukarya the glycerol backbone is connected to the fatty acids via —- linkage
ester
in archaea the glycerol backbone is connected to the fatty acids via —- linkage
ether
what are the differences among the phospholipid structure of archaea vs. bacteria and eukarya
1) ether linkage
2) the lipid part is made of isoprene