Bacteria Flashcards
Are bacteria prokaryotic or eukaryotic?
Prokaryotes
What is in the cytoplasm (cell contents)
Contains no compartments or distinct organelles.
Genetic material is not membrane bound in a nucleus and the cell is bound by the cell wall - (prokaryotic)
Bacteria Kingdom called?
Monera - Alone
Divisions of bacteria
Archaebacteria and eubacteria (all other bacteria)
How are eubacteria divided?
Mode of nutrition
Name the 3 types of eubacteria?
Photoautotrophs, Chemoautotrophs, Heterotrophs
What are Photoautotrophs?
‘Light self-feeders’ contain chlorophyll and use energy in the from of light to produce nutrients.
What are Chemoautotrophs?
‘Chemical self-feeders’ derive the energy they need from inorganic molecules. Such as Ammonia NH4
What are Heterotrophs?
‘Other feeders’ obtain their nutrients from organic molecules.
What bacteria cause disease?
Heterotrophs - only some cause disease. Human are also heterotrophs.
Cell wall
Rigid support, protects against osmotic pressure and targets of antibiotics.
Ribosome
protein synthesis and are the target of antibiotics
Plasmid
optional extra DNA
Capsule
Protects again immune system
Flagella
‘little tongue’ move/swim
Pilus
Attachement or sex
Peptidoglycan
Is what the GRAM stain either sticks to or not.
Gram NEG
Thinner peptidoglycan, so the gram stain can’t stick to the peptidoglycan when the alcohol is added. Majority are pathogenic and highly infectious. BAD=Pink
Gram POS
Thick peptidoglycan, gram stain can stick to the peptidoglycan when the alcohol is added. Very few are pathogenic. GOOD=Purple
Steps for GRAM staining
- Fixation
- Add crystal violet
- Iodine treatment
- Decolorisation (alcohol)
- Counter stain (safranin)
5 shapes of Bacteria
Spirochaetes, Vibro, Bacilli, Staphylococci, Streptococci.
Spirochaetes
Spiral - treponema palladium
Vibro
Comma - vibrio cholerae
Bacilli
Rods - Bacillus anthracis
Staphylococci
Groups of round shaped bacteria - Staphylococcus Aureus
Streptococci
Chains of round shaped bacteria - Streptococcus pyogenes
Diplococci
Pairs of cocci - Neisseria gonorrhoaea
Obligate aerobes and example
Bacteria which require the presence of oxygen - mycobacterium tuberculosis.
Obligate anaerobes and example
Organisms that are unable to tolerate the presence of oxygen - clostridium tetani (tetanus)
Various gram pos species are able to form?
Spores
Spores are?
Microorganism develops a protective capsule in which it lies in a dormant condition. Able to tolerate extreme conditions and resistant to chemical disinfectants.
However when favourable condition return it will germinate and the organism will resume its active lifecycle. - Bacillus anthracis
How do they reproduce?
Duplicate their genetic material and divide into two. (Binary fission)
3 types of Extremophiles?
Thermophile, Mesophile and Psycrophiles
Thermophile?
optimal growth between 45-122 degrees
Mesophile
20-45 degrees
Psycrophiles
-15 to 10 degrees or lower
Mycoplasmas?
Different structure and lifestyle to other bacteria
Smallest free living organisms, unique among prokaryotes because they lack a cell wall.
Cant gram stain them
Kill them with penicilins
Rickettsias?
Different structure and lifestyle to other bacteria
Gram neg, non-motile Cocci or thread obligate intracellular parasites - don't make their own ATP need energy from their host cell. have cell walls but leaky cell membranes live in lice, tics and fleas
Chlamydia?
Different structure and lifestyle to other bacteria
Gram variable due to cell wall structure
Obligate intracellular parasites - need ATP from its host
Two phase life cycle
Meningococcal disease
Gram neg,
from diplococci
Pharyngitis
Caused pneumonia - by legionella (associated with compost) likes to live in contaminated water.
Pertussis
Whooping cough - causes the killing of the cilia and the coughing is bought on by the ticking of the growing back of the cilia.
No point in giving antibiotics.(unless you catch it early).
