Monera (Bacteria) Flashcards
Whats a micro-organism?
Small living things
Parts of a bacterial cell
(always present)
-Cell wall
-Cell membrane
-Cytoplasm
-Ribosome
-Storage granule
-Loop of DNA
Parts of a bacterial cell
(sometimes present)
-Capsule (slime layer)
-Flagella
-Plasmid
Function of flagella
Make the bacteria mobile
What do plasmids contain?
Genes that are responsible for bacterial resistance to antibiotics
Classification of Bacteria
(3 types)
-Round
-Rod-shaped
-Spiral
Whats the method by which bacteria reproduce?
Binary fission
3 steps of binary fission
-DNA strand copies itself so now there’s two identical strands
-The cell elongates with a stand of DNA attached to each end
-Cell splits in two
Why do some bacteria have endospores?
To withstand harsh (unfavourable conditions)
3 steps of endospore formation
-Chromosome replicates
-New stand becomes enclosed by tough-walled endospore
-Parent cell breaks down and endospore remains dormant
Autotrophic
Means an organism can make its own food
Heterotrophic
Means an organism takes in food made by other organisms
Chemosynthesis
Is the production of food using energy released from chemical reactions
Saprophytes
Are organisms that feed on dead sources
Parasites
Obtain their food from a live host
Photsynthetic
Use light to make their food
Factors affecting the growth of bacteria
-Temperature
-Oxygen concentration
-pH
-Presure
Whats a facultative anaerobe?
Can respire with or without oxygen
Whats an obligate bacteria?
Can only respire in the absence of oxygen
Economic benefits of bacteria
-Used to convert milk to butter, cheese and yogurt
-Involved in the production of antibiotics
Economic disadvantages of bacteria
-Bacteria causes food decay
-Causes human and animal diseases
Whats pathogenic bacteria?
Causes disease
What are antibiotics?
Chemicals produced by micro-organisms that stop the growth/kill other micro-organisms without damaging human tissue
What does it mean for bacteria to be antibiotic-resistant?
Bacteria isn’t affected by the antibiotic being used
What causes antibiotic resistance?
-Caused by mutations
>from overuse of antibiotics
or
>failure of the patient to complete their treatment of antibiotics
5 phases in the growth curve of bacteria
-Lag phase
-Log phase
-Stationary phase
-Decline phase
-Survival phase
What happens in the lag phase?
-Bacterial numbers remain constant
-Bacteria are adapting to their new enviroment
What happens in the log phase?
-Bacterial number increase rapidly
-Reproducing at their maximum rate because of ideal conditions
What happens in the stationary phase?
-No increase in bacterial numbers
-Birth rate = death rate of the bacteria
-Lack of food, space and oxygen
What happens in the decline phase?
-Number of bacteria falls rapidly
-Death rate> birth rate of bacteria
-Lack of food, space and oxygen
What happens in the survival phase?
-A small number of bacteria survive by remaining dormant as spores
What is batch culture?
Is the growth of cells in a sealed container (bioreactor) over a short period of time and under ideal conditions until all the nutrients are used up
What is continuous flow food processing?
Is the growth of cells in an open container (bioreactor) where nutrients are added and the end products are removed all the time at a rate that maintains the volume of liquid and number of cells
What is a bioreactor?
Is a vessel in which living cells or their products are used to make a product
