Bacteria Flashcards
(17 cards)
what are the 3 classifications of bacterial cells
- Gut microbiota → Beneficial gut bacteria which aid in digestion, vitamin production and protection against pathogens
- Probiotics → live microorganisms which may give health benefits when consumed in adequate amounts
- Pathogenic Bacteria → Bacteria that cause disease by invading, releasing toxins and triggering immune responses
what are the different types of bacterial shapes (10)
Cocci - ball
Bacilli - pill shapes
Club rod - dumbbell-shaped
Vibro - banana-shaped
Spirillum
Helical form
Spirochete
Filamentous
Hypha
Stalk
How are bacteria identified through staining (4)
Gram ve- = pink & thin walled (vesicles)
Gram ve+ = purple & thick walled (channels)
What are the structures and functions of a bacterial cell that enables infection? (3)
- Capsule - protects the bacteria from desiccation by helping cells adhere to surfaces. And providing resistance to phagocytosis.
- Fimbriae - which assists with adherence to host and colonisation (infection).
- Pili - assist in surface attachment and facilitate conjugation (genetic exchange).
What is the structure and function of a bacterial cell that enables motility. (2)
- The flagellum assists in swimming and bacterial mobility
- they are helical in shape and exist in 3 different arrangements: PERITRICHOUS, POLAR, LOPHOTRICHOUS
What are the steps of sporolation (6)
- vegetative growth stops and DNA is duplicated.
- septum forms and divides the cell unsymmetrically.
- larger compartment engulfs smaller compartment.
- forespore is formed in the mother cell (smaller compartment).
- peptidoglycan material is layed down between the two membranes surrounding the forespore.
- the cell is degraded and the endospore is released.
What is the cytoplasmic membrane (2)
- separates the cytoplasm from the external environment
- Highly selective allowing the concentration of specific metabolites and the excretion of waste products.
What are endospores (3)
- highly differentiated cells resistant to heat, chemicals and radiation.
- They are the dormant stage of the bacterial life cycle
- only present in gram ve+ bacteria
What are the phases in the bacterial growth curve (4)
Lag phase
Log phase
Stationary phase
Death phase
What are the big 6 food-borne illnesses (6)
Norovirus
Hepatitis A
E-coli
Salmonella (non-typhoidal)
Salmonella (typhoidal)
Shingles
what are the 3 arrangements of flagellum (3)
Peritrichous
lophotricous
polar
what are the types of bacterial infections (3)
- Streptococcus pneumoniae - pneumonia
- Escherichia coli (E.coli) - food poisoning, UTIs
- mycobacterium tuberculosis - tuberculosis
what are Enterobacteriaceae (4)
- many species are a part of normal gut microbiota
- 80% clinically significant gram ve- bacilli
- Account for most gram ve- healthcare-associated infections
- meningitis, bacillary dysentery, gastroenteritis, UTI, septicaemia
What is the bacteria cell structure (6)
- capsule
- cell wall
- plasma membrane
- nucleoid
- ribosome
- plasmid
what is the cyanobacteria cell structure (14)
- slime coat
- capsule
- mucoid sheath
- outer membrane
- peptidoglycan layer
- inner membrane
- phycobilisome
- lipid droplet
- carboxysome
- cyanophycin granule
- nucleoid
- vacuole
- ribosome
- thylakoid
what is the bacterial cell surface (5)
- capsules, slime layers, fimbriae, pili
- polysaccharide layers - thick/thin, rigid/flexible
- assist in attachment to surfaces (fimbriae & pili)
- protect against phagocytosis
- resist desiccation
what are pili (3)
- filamentous protein typically longer than fimbriae
- assist in surface attachment
- facilitate genetic exchange between cells (conjugation)
