Bacteria (monera) Flashcards
Bacteria
-microorganisms - cannot be seen with the naked eye
- monera
Are prokaryotic cells and unicellular
Cell membrane
Inner folding called mesosphere which are for respiration
Cell wall
Prevents bacteria from swelling and bursting when in less concentrated solutions
Plasmid
Contains a loop of dna
Capsule
Protection
Flagella
Movement
3 types of bacteria
1
Spherical
Eg pnemonia
Types of bacteria
2
Rod
Eg TB
Types of bacteria
3
Spiral
Eg cholera
Autotrophic bacteria
Can make there own food
Eg photosynthetic - use light energy to make food
Heterotrophic bacteria
Cannot make there own food
Eg saprophytic - live off dead organic matter
Eg parasitic - take food from live host causing harm
Bacterial reproduction
Binary fission - asexual
Binary fission
- bacterial dna replicates
- cell elongated and two loops of dna move to opp sides of cell
- cell wall grows and cell splits
- two identical daughter cells are formed
Endospore formation
When
Occurred during stationary or decline phase of growth curve
Endopsore formation
Benefit
Produced so some bacteria can survive harsh and unfavourable conditions
Endospore formation
Process
-bacterial DNA replicates and moves to the two ends of the cell
-cell shrinks as water is lost from cytoplasm
-thick walled capsule forms inside cell around one dna strand = Endospore
Factors affecting growth of bacteria
Temp - high temps cause enzymes to become denatured
PH- its enzymes become denatured in unsuitable pH
- oxygen concentration - aerobic bacteria require oxygen for respiration Anaerobic do not
Beneficial bacteria
Antibiotics can be formed by some microorganisms
Bacteria in the colon help produce vit b and k
Harmful bacteria
Cause food decay
Pathogenic bacteria can cause diseases - tb typhoid cholera
Antibiotic
A chemical produced by microorganisms to kill other micro organisms without damaging human tissue
How antibiotic resistant has developed
Misuse or over use of antibiotics
Food processing
Bio processing
Involved the use of micro organisms
To form products eg yogurts cheese
Food processing
Bioreactor
A vessel in which products are made by microorganisms
Methods of productions
Batch culture
- fixed amount of nutrients added to bioreactor at the start
- organisms go through all phases of the growth cycle
Methods of production
Continuous flow
-nutrients are constantly being added to the bioreactor
- organisms are maintained in the stationary growth phase
