Intro to bacteria Flashcards
What is the main function of the ribosome?
Protein synthesis
What is the main function of the plasma membrane?
Allow for diffusion
What is the main function of the cell wall?
Structure and support
What is the main function of the capsule?
Defence mechanism
What is the main function of the flagellum?
Motility
What is the main function of the fimbriae?
Attachment
What is the structure of the gram positive cell wall?
Plasma membrane
Periplasmic space
Peptidoglycan
What is the structure of the gram negative cell wall?
Plasma membrane
Periplasmic space
Peptidoglycan
Lipopolysaccharide
What is the function of penicillin binding proteins?
Synthesise peptidoglycans
What are peptidoglycan?
Carbohydrate polymers cross linked with 3-5 amino acids
What are the fimbriae and what is their structure?
Attachment pilus, thinner and shorter than the flagellum
What are spores?
Thick, protective cell wall that is resistant to changes is habitat
What are plasmids?
Circular, double stranded DNA molecule that can be transferred between bacteria
What is the pilus?
Thin, hair like projections used to join 2 bacterium for plasmid transfer
Between what types of bacteria is plasmid transfer most common?
Gram negative to negative
Gram positive to positive
Rarely negative to positive or vice versa
How does bacterial genetic material replicate?
Binary fission
What processes are involved in the transfer of DNA?
Conformation
Transformation
Transduction
What is a bacteriophage?
Virus that attacks bacteria and replicates within it
How do bacteriophages work?
They inject genetic material or themselves enter the bacterial cell and integrate their DNA into the bacteria’s chromosome, utilising their cell resources to replicate
What are the 2 cycles involved in bacteriophages and when are they used?
Lipid cycle- when bacteriophage enters bacteria
Lysogenic cycle- when genetic material is injected into the bacteria
When can individual bacteria be seen?
x1000 oil immersion microscope and stain
What are stains used to determine?
Whether bacteria are dead or alive
What is contained in MacConkey’s agar?
Lactose, bile salt, crystal violet
What shape are cocci?
Spherical
What shape are bacilli?
Rod shaped
How are strep grouped?
Chains
How are staph grouped?
Clusters