bacteria Flashcards
structure: what are the 7 parts of the bacteria cell?
- plasma membrane
- capsule
- flagella
- cell wall
- nucleoid
- plasmid
- cytoplasm
structure: what is the cell wall made of?
peptidoglycan and proteins
structure: what does the plasma membrane do?
controls what goes in and out of the cell
structure: what do they have instead of a nucleus?
plasmid- circular strand of DNA
structure: what is the flagella?
tail-like structure - allows movement
structure: what is the capsule?
a slime-like layer outside the wall -protects the bacterium from drying out
morphology: what are the 3 shapes of bacteria?
- coccus
- bacilli
- spirillia and leptospiriosis
morphology: what are the three types of cocci and an example?
- diplococci- e.g. pnemonia
-streptococci- e.g. strangles and mastitis
-staphylococci- e.g. mastitis and skin infection
morphology: what is an example of bacilli?
e.g.
-anthrax
-E.coli
- TB
- salmonella
morphology: what is an example of spirilla and leptospirosis?
e.g. campylobacter
growth: how do bacteria grow?
by microbial growth
growth: what is microbial growth?
- an increase in the number of cells
- rather than in the size of individual cell
- studied as a population not individual
growth: how does microbial growth work?
- its a colony
- it arises from a single spore, vegetative cell or group
- from the same micro-organism that attaches into a clump or chain
growth: what shows the phase of growth?
a growth curve
- shows population of bacteria in a batch culture changes with time
- logarithmic graph is plotted and show the varies stages of growth
growth: what is the lag phase?
bacteria is active but reproducing slowly
growth: what is the log phase?
Once the bacteria starts to divide the numbers increase at a constant rate- which reflects the doubling time
growth: what is the stationary phase?
bacteria uses up all available nutrients
growth: the death phase?
after a while rate of death becomes greater then cell division
growth: what are the oxygen requirements?
they can be an aerobes- require oxygen
or anaerobes- do not require oxygen
growth: what is their PH?
thrive better in acidic to neutral environments
growth: what is the temperature requirements?
psychrophiles - 0- 20 degrees C
mesophiles - 10- 45 degrees C
thermophiles - 45- 100+ degrees C
growth: how do they reproduce?
they reproduce sexually and asexually
-binary fission - assexual
-conjugation- sexual
-transduction -sexual
-transformation- sexual
growth: how does binary fission work?
parent cell divides to form identical daughter cells
growth: how does conjunction work?
DNA is transferred between the bacterium
growth: how does transformation work?
bacterium takes DNA from environment shed from other bacteria
