Chapter 20 - Monera (Bacteria) Flashcards
What does the cell wall do?
prevents bacteria from bursting during osmosis
What does cytoplasm do?
contains ribosomes and storage granules
What kind of cell is in bacteria?
prokaryotic
What does DNA do?
contains chromosomes which give the primary traits
What does a capsule do?
protects the bacteria
What does a mesosome do?
used for respiration, help during cell division
What does plasmid do?
contains genes responsible for antibiotic resistance
What does a flagellum do?
allows movement
What are the 3 shapes a bacteria can be?
- coccus (round)
- bacillus (rod)
- spirillum (spiral)
Give an example of a coccus bacteria?
pneumonia
Give an example of a bacillus bacteria?
e. coli
Give an example of a spirillum bacteria.
cholera
How do bacteria reproduce?
asexual reproduction - binary fission
How often do bacteria reproduce?
every 20 minutes
What name is given to bacteria that evolves?
mutations
How do bacteria mutate?
they evolve to be antibiotic resistant
Name a bacteria that is resistant to antibiotics.
MRSA
What are endospores?
tough walled spores capable of surviving harsh conditions
What can endospores do that regular bacteria cannot?
difficult to kill - withstand high temp, lack of food and water
How do bacteria get nutrients?
theyre autotrophic and heterotrophic
What does autotrophic mean?
they make their own food
What are the 2 types of autotrophic bacteria and how do they make their own food?
photosynthetic bacteria - they have chlorophyll on their membranes , allows them to make food through photosynthesis
chemosynthetic bacteria - they use chemical reactions involving ammonia and iron compounds
What does heterotrophic mean?
takes in their own food
What are the 2 types of heterotrophic bacteria and how do they get their food?
saprophytic bacteria - has enzymes that digest dead organic matter - decomposers parasitic baceria (parasites) - use a living host for food, harm the host
What 5 factors affect bacteria growth?
- temperature
- oxygen concentration
- ph
- external solute concentration
- change in pressure
How does a change in temperature effect the growth of bacteria?
most prefer between 20 and 30 degrees celcius
high temperatures denature the enzymes
low temperatures slow down growth
How does a change in oxygen concentration effect the growth of bacteria?
aerobic bacteria - require oxygen for respiration
anaerobic bacteria - do not require oxygen for respiration
What is a facultative anaerobe?
respire with or without oxygen
What is a obligate anaerobes?
only respire in the absense of oxygen
How does ph effect the growth of bacteria?
unsuitable ph will denature enzymes
most grow at or near neutral
How does external solute concentration effect the growth of bacteria?
bacteria can gain or lose water through osmosis
if external solution has lower water then the water will move out - dehydration - food preservation
if external solution has higher water then water will move it - bacteria thrive
How does a change in pressure effect the growth of bacteria?
growth is inhibited by high pressure - bacteria walls are not strong enough
How does bacteria benefit the economy?
lactobacillus - makes cheese/ yoghurt
genetically modified bacteria used to make medicine, alcohol, food flavourings
What are the disadvantages to the economy of bacteria?
causes food to decay
causes disease in plants and animals
Who discovered antibiotics?
sir alexander fleming - penicillin
What are antibiotics?
chemicals produced by micro organisms that stop the growth of other micro organisms without damaging human tissue
What is bad about antbiotics for humans?
it kills all bacteria even good bacteria
How does antibiotic resistance occur?
bacteria mutates
What is causing more antibiotic resistanced?
the overuse of antibiotics
failing to complete antibiotic treatment
What are the 5 stages of the growth curve for bacteria?
a - lag b - log c - stationary d - decline e - death/survival
What happens during lag?
bacteria is adapting to the environment
What happens during log?
ideal conditions for max reproduction
What happens during stationary?
birth rates is equal to death rate
What happens during decline?
death rate is greater than birth rate
What happens during death or survival?
bacteria become dormant until favourable conditions occur
What is bio processing?
using living things to produce useful materials
What are some products of using bacteria for food processing?
alcohol, dairy products, food flavourings
What are the 2 types of food processing used for bacteria?
batch culture
continuous flow culture
What is batch culture?
fixed amount of nutrients
micro organisms go through all the phases and product is formed for a short time
What is continuous flow culture?
nutrients added continually
micro organisms kept n the log phase all the time
products formed all the time for a long time
