16. Monera Flashcards
Shapes of Monera and diseases caused?
Spirillum- Cholera
Bacillus- Tb and Tetanus
Cocci- Sore throat and pneumonia
Main features of monera (2)
Unicellular
Prokaryotes
Draw and label bacteria cell
Flagellum Plasmid Capsule Wall Membrane Granules Mesomeme Pili Ribosome
Function of: Cell wall Cytoplasm Ribosome Granules Capsule Flagella Plasmid Pili Mesomeme
Cell wall- shape and structure Cytoplasm- holds organelles Ribosome-makes protein Granules-storage Capsule-protection Flagella-movement Plasmid-circular piece of DNA containing genes Pili-sticks to surfaces Mesomeme-respiration
Bacterial nutrition types
Autotrophic
Can make its own food
Heterotrophic
Cannot make its own food
Autotrophic types (2)
1.Photosynthetic
Makes own food using light energy.
Eg. Purple sulfur bacteria
2.Chemosynthetic
Use energy from chemical reactions to make food.
Eg. Nitrifying bacteria used in nitrogen cycle
Heterotrophic types (2)
- Saprophytic
Lives off dead organic matter
Eg. Bacteria in soil - Parasitic
Live off living organisms
Eg. Disease causing bacteria
Bacteria reproduction
Asexual
Binary fission
Binary fission process
- DNA strand attaches itself to membrane and replicates
- The cell elongates and DNA strands separate.
- Cell divides in two and separates.
- Two identical daughter cells are formed.
What happens when conditions become unfavourable?
When does it happen?
An endospore forms.
After DNA replicates.
Endospore forms around replicated DNA
Parent cell breaks down and dies, endospore dormant.
When conditions favourable endospore absorbs water and breaks walls
Reproduces by Binary fission
Factors affecting growth
Optimum temperature...20-30'C, Optimum ph...7, Optimum oxygen concentration, Absence of competition and toxins Abundant source of food
Oxygen concentration (2 types)
Aerobic
Need oxygen
Eg. Streptococcus
Anaerobic
Do not need oxygen
Eg. E.Coli
Economic importance (Benefits)
- Lactobacillus used in dairy products
- Antibiotics
- Bacteria in colon produce vitamins
- G.M.O used in insulin, drugs, flavourings, vitamins. Eg. E.Coli
Economic importance (Harmful)
- Cause diseases.
Eg. Cholera caused by vibrio
Tb caused by Mycobacterium - Spoil food
- Cause tooth decay
Pathogenic
Lives off host and causes disease
Symbiotic
Relationship between two organisms where both benefit.
Eg. Bacteria that produces vitamins b and k in colon
Antibiotics
What they are and what they do
Substance produced by micro-organisms
They stop the growth of or kill other micro-organisms.
Do not affect viruses!!
Antibiotic resistance
When bacteria develop antibiotic resistance; antibiotics have no effect on them.
Bacteria strains have developed which are resistant to all known antibiotics.
Known as multi-resistant bacteria
Eg. MSRA
Misuse of antibiotics and consequences
Results in increased growth of antibiotic resistant bacteria… Cannot control bacterial growth
Misuse:
1. Failure to complete prescription- can survive and regrow
- Over use- body becomes immune so no effect on bacteria
Growth curve of bacteria
Name 5 stages
Lag Log Stationary Decline Death/ Survival
Lag phase
What happens?
Why?
What?
Small increase in bacteria numbers
Why?
Bacteria is adapting to new environment.
Log
What and why?
What?
Rapid growth in bacteria numbers
Why?
Optimal conditions
Stationary phase
What and why?
What?
Equal birth and death rate so numbers stay the same.
Why?
Competition and toxins
Decline phase
What and why?
What?
Rapid death rate
Why?
Lack of nutrients and a toxic environment.
Conditions not optimum
Death/ Survival phase
Small number survive as endospore said
Rest die due to unfavourable conditions
Bacteria and food processing
Name 2 types
Batch culture method
Continuous flow method
Bioprocessing definition
Technique where micro-organisms, living cells or their components are used to produce food.
Eg. Yoghurt, beer, wine, cheese
Bioreactor
Stainless steel vessel where Bioprocessing takes place
Batch culture method
Explain
When bacteria stopped?
Micro-organisms and fixed amount of nutrients in bioreactor at the start.
Stopped before decline stage.
Product removed at end.
Bioreactor cleaned and reused.
Continuous flow method
Explain
When bacteria stopped?
Bacteria in at start.
Nutrients added continuously to bioreactor.
Product removed constantly
Bacteria kept at Log phase
Not used often because it is hard to maintain at log stage… ie at optimum conditions.
Asepsis vs. Sterility
Asepsis: Steps taken to reduce the amount of disease causing microbes.
Sterility: Absence of all microbes
