Monera (Bacteria) Flashcards
What does the cell wall do
Prevents the bacteria from bursting during osmosis
What does cytoplasm do
Contains ribosomes and storage granules - no mitochondria
What does DNA do
Contains chromosomes which give the primary traits
one chromosome
What is only sometimes present in bacteria
Capsule
Mesosomes
Plasmid
Flagellum
What is the function of the capsule
Protection
What is the function of a mesosome
used for respiration
helps during cell division
What does a plasmid do
contains genes responsible for antibiotic resistance
What is the function of the flagellum
allows movement
What are the shapes a bacteria can be
- Coccus (round)
- Bacillus (rod)
- Spirillum (spiral)
Name an example of a coccus bacteria
pneumonia
Name an example of a bacillus bacteria
tuberculosis (TB)
e.coli
Name an example of a spirillum bacteria
cholera
How do bacteria reproduce
asexual reproduction - binary fission
How often do bacteria reproduce
every 20 mins
What are mutations in bacteria
bacteria that evolve very fast
How do bacteria mutate
they evolve to be antibiotic resistant
Name a bacteria that is antibiotic resistant
MRSA
What are endospores
tough walled spores capable of surviving harsh conditions
What can endospores do that regular bacteria cannot
withstand high temp , lack of food and water and most poisons - difficult to kill
How do bacteria get nutrients
they are autotrophic and heterotrophic
What does autotrophic mean
an organism makes its own food
What are the types of autotrophic bacteria and how do they make their own food
Photosynthetic - chlorophyll on membranes
Chemosynthetic - use reactions involving ammonia, sulphur and iron compounds
What does heterotrophic mean
an organism takes in food made by other organisms
What are the types of heterotrophic bacteria and how do they get their food
Saprophytic - enzymes digest dead organic matter
Parasitic - use a live host for food , usually cause harm
What 5 factors affect bacterial growth
Temperature Oxygen concentration pH External solute concentration Pressure
How does temperature affect the growth of bacteria
Prefer 20°C-30°C
high temps denature enzymes
low temps slow down growth
How does oxygen concentration affect the growth of bacteria
Aerobic - require O2 for respiration
Anaerobic - do not require O2 for respiration
What is a facultative anaerobe
respire with or without oxygen
What is an obligate anaerobe
only respire in the absence of oxygen
How does pH affect the growth of bacteria
unsuitable pH will denature enzymes
Most grow at neutral
How does external solute conc affect the growth of bacteria
external soln has high solute - then bacteria dehydrates
external soln low solute conc- water drawn in
How does pressure affect the growth of bacteria
Growth inhibited by high pressure
What are the economic benefits of bacteria
Converts milk to yogurt and cheese (lactobacillus)
Genetically modified bacteria used to make products like insulin , drugs , vitimins
What are the economic disadvantages of bacteria
cause plant and human disease (pathogens)
cause food to decay
What are antibiotics
Chemicals produced by micro-organisms that stop the growth of, or kill, other micro-organisms without damaging human tissue
Who discovered antibiotics
Sir Alexander Fleming
What is a disadvantage to humans because of antibiotics
antibiotics kill ALL bacteria in the body - good and bad
How does antibiotic resistance occur
antibiotic resistant bacteria have developed from bacterial mutations
What is causing more antibiotic resistance
overuse of antibiotics leads increased growth of anti-biotic resistant bacteria
failure to complete full treatment allows bacteria to survive and regrow
What is the 5 stages of the growth curve for bacteria
- Lag
- Log
- Stationary
- Decline
- Death/Survival
What happens during the lag stage
bacteria adapt to their environments
bacterial numbers remain constant
What happens during the log stage
bacterial numbers increase rapidly
ideal conditions for max. reproduction
What happens during the stationary stage
birth=death
no increase in bacterial numbers
limited resources - food, space , moisture, oxygen
toxic environment
What happens during the decline stage
number of bacteria falls rapidly
death > birth rate
What happens during the death/survival stage
bacteria become dormant until conditions are favourable again
What are the 2 types of food processing used for bacteria
Batch culture
Continuous flow culture
What products are made from using bacteria in food processing
dairy products - yogurts , cheeses
alcohol products
vitamins
What is batch culture
The growth of cells in a sealed container over a short period of time and under ideal conditions until all the nutrients are used up
What is continuous flow culture
The growth of cells in an open container where nutrient are added and the end products are removed all the time at a rate that maintains volume of liquid and the number of cells
What is a bioreactor
A vessel or container in which living cells or their products are used to make a product
What is bio-processing
the use of bacteria and other organisms to produce a wide range of products
