module 2 (from notes) Flashcards
are bacteria limited on how much they can replicate?
no, their only limit is their environment/resources
describe how bacteria grow as a species
they grow in size in their species (numbers). they do not grow as humans do in size
how do bacteria grow?
they double
describe the “surface area to volume ratio”
at a small size, the ratio is small and very efficient. cell exchanges with its world, gets gasses & nutrients, etc.
as the ratio gets bigger, the SA to V ratio gets worse and the diffusion isn’t as efficient
why cant you have huge bacteria?
there’s not enough surface area to volume exchange to efficiently get everything diffused out of/into the cell that it needs to survive
how do bacteria reproduce?
binary fission
describe the steps of binary fission
- DNA has to get replicated
- cell starts out with one circular chromosome
- a whole other circle chromosome has to get produced
- the two circles move to different ends of the cell
- SEPTUM pierces off in the middle
- pops apart into 2 separate cells
what is important about the septum?
the cell wall has to be re-established here
are bacteria clones?
yes. clones = exact replica
what doubles faster than any other bacteria?
E. coli
what is a closed growth system?
a flask or incubator. humans can also be considered a closed growth system.
describe the “standard closed system growth”
- lag phase (bacteria have a period of time where they get used to their environment)
- log phase (they grow rapidly… exponential growth)
- stationary phase (dying cells = replicating cells)
- death phase (more cells dying than are replicating)
describe mutations
when DNA is getting replicated, the cells will all be the same species but might have some small genetic differences as the population grows
