Monera (Bacteria) Flashcards
In relation to micro-organisms like bacteria and fungi, describe their distribution in nature.
they can survive in all habitats
or
they are found everywhere
Explain the terms sterility and asepsis.
S: absence of all (micro) organisms
A: absence of pathogens
Are bacteria prokayotic or eukaryotic? Justify your answer.
prokaryotic: without nucleus or without membrane-bound organelles
Bacteria reproduce asexually, name and describe this process.
binary fission:
- DNA replicates
- DNA moves to both ends of the cell
- cell elongates
- cell divides in two/two identical cells formed
Explain the term pathogenic.
disease causing
Give a possible effect of the misuse of antibiotics.
(antibiotic) resistance
What is microbiology?
study of microorganisms
What are microorganisms? Give 3 eg’s.
small living things,
eg: protists, bacteria, fungi
Comment on cell of monera.
unicellular/single celled
Name the 6 parts of the basic structure of a bacterial cell that are always present.
cell membrane
cell wall
cytoplasm
ribosome
storage granule
DNA loop
Name the 5 parts of the basic structure of a bacterial cell that are sometimes present.
capsule/slime layer
flagella/flagellum
plasmid
mesosome
endospore
Function of cell wall and what is it made up of?
protects the cell from swelling with water and bursting. composed of sugars and proteins
Describe the cell membrane.
allows certain substances enter and leave, it surrounds the bacteria and is selectively permeable
Function of capsule/slime layer?
further protection against other micro-organisms
What does a bacterial chromosome consist of?
1 DNA loop
Decribe the plasmid.
contains DNA loops, responsible for antibiotic resistance
Describe the cytoplasm.
contains ribosomes and storage granules for metabolic reactions/food and waste
Describe the flagella.
tail like structures allowing the bacteria to move
What does motile mean?
move by themselves
Function of storage granules?
stores nutrients, eg: glycogen
What 2 things to monera not contain?
mitochondria or chloroplast
Function of mesosome?
aids respiration / cell division
How many shapes of bacteria are there?
3
Name the bacterial shapes.
spherical/round,
rod,
spiral
Give an example of a round/spherical bacteria.
pneumonia
Give an example of a rod bacteria.
tetanus (lockjaw)
Give an example of a spiral bacteria.
cholera
Endospores are a method of what?
survival
Some bacteria can survive in harsh conditions by producing what?
an endospore
Describe the main events of endspore formation.
- DNA replicates
- moves to ends of the cell
- shrinkage of cytoplasm
- thick wall form
- inside original cell
- encloses DNA
- cell rounds up
Whats mutation?
a change in the amount or strucutre of DNA
Bacteria produce identical offspring as they reproduce ____, there is no ____
asexually
variation
What are antibiotics?
chemicals that kill bacteria
/
chemicals produced by micro-organisms that inhibit the growth of, or kill, other micro-organisms
What antibiotic was first discovered and by who?
penicillin by Fleming
What do antibiotics not affect?
viruses
Overusing antibiotics can lead to?
the development of resistant bacteria
Give 3 ways antibiotic resistance can occur.
overuse
misuse
mutation
The gene for antibiotic resistance is found on the?
plasmid
What does antibiotic resistance mean?
these bacteria are not affected by the antibiotic thats being used
Give 2 potential abuses of antibiotics in medicine?
overuse
failure to complete treatment
Bacteria get their food in how many different ways?
4
The ways of getting their food is split into what?
autotrophic and heterotrophic
Autotrophic meaning?
make their own food
Two types of autotrophic nutrition for bacteria?
photosynthetic bacteria
chemosynthetic bacteria
Explain photosynthetic bacteria + eg.
chlorophyll absorbs light (sun) to make food
Eg: purple sulphur bacteria
Explain chemosynthetic bacteria + eg.
make food using energy from chemical reactions
Eg: nitrifying bacteria in nitrogen cycle
Chemosynthesis means?
the production of food using energy releaed from chemical reactions
Two types of heterotrophic nutrition for bacteria?
saprophytes
parasites
Heterotrophic means?
take in food from other organisms
Saprophytes are?
organisms that take in food from dead organic matter
Describe saprophyte as nutrition + eg.
take in food from a dead host/dead organic matter, acting as decomposers
Eg: bacteria of decay (in soil)
Parasites are?
organisms that take in food from a live host and usually cause harm
Describe parasites as nutrition + eg.
take in food from a live host causing harm
Eg: tetanus, pneumonia
Name 5 factors affecting bacterial growth (+1 extra minor one).
1) temperature
2) pH
3) pressure
4) external solute concentration
5) oxygen concentration
+) food
Bacteria normally grow best between what temp?
20 -30 degrees C
An unsuitable temperature will do what to the enzymes?
denature
Cooler/lower temperatures do what to enzymes and bacterial growth?
slow
Optimum pH for bacteria is?
pH 7 = neutral
Where in the body has bacteria functioning at a low pH
stomach
At high pressure, what happens bacteria?
bacterial cell walls collapse
If external solution is of higher concentration what happens the water?
leave bacterial cell
If internal solution is of higher concentration what happens the water?
enter the cell
If external solution is of lower concentration what happens the water?
enter the cell
Aerobic bacteria require oxygen for what?
respiration
Do parasitic bacteria require or not oxygen to respire?
dont require
Faculutative anaerobes respire how?
with or without oxygen
Obligate anaerobes respire how?
only without oxygen
Example of obligate anaerobes?
tetanus/lockjaw
Example of anerobic bacteria?
tetanus
Example of aerobic bacteria?
streptococcus/sore throat
2 economic importances of bacteria?
- bacteria lactobacillus is used to convert milk to cheese and yoghurt.
- genetically modified bacteria produce insulin.
- vaccine production
- gut bacteria produce vitamins K and E
- aerobic bacteria for vinegar production
- bacteria is essential for nitrogen and carbon cycles
2 disadvantages of bacteria?
- cause disease (pathogens), food poison (ecoli), cholera.
- some cause food decay
List 5 stages of bacterial growth.
- lag
- log
- stationary
- decline
- death/survival
In lag phase:
growth ? death
birth rate ? death rate
=
In log phase:
growth ? death
birth rate ? death rate
>
In stationary phase:
growth ? death
birth rate ? death rate
=
In decline phase:
growth ? death
birth rate ? death rate
>
Explain lag phase.
very little growth, bacteria are adapting to their environment
Explain log phase.
numbers rapidly increase, due to ideal conditions
Explain stationary phase.
slows down with no increase due to the lack of food/space/moisture/oxygen/build up of toxic waste
Explain decline phase.
numbers decline due to death rate being higher than birth rate/growth
Explain death/survival phase.
not all die, some survive and form spores known as endospores
Batch food processing?
organisms go through all phases of the growth curve
or
fixed amount of nutrients added at start
or
bioreactor emptied at end
Continuous flow?
maintained in one (log or stationary) growth phase
or
nutrients constantly added
or
products constantly removed
How dp certain bacteria respond to unfavourable conditions:
endospore forms
Whats a bioreactor?
a vessel/container in which living things are used to make a product
Give an example of batch culture processing.
antibiotics
Give an example of continuous flow processing.
single-celled protein
