Bacteria 1 Flashcards
Prokaryotes - lack
nucleus, membrane bound organelles
Prokaryotes - typically have ___ chromosome
single, double stranded circular DNA chromosome
Prokaryotes - ribosome
smaller! important because we are able to target this
Prokaryotes - cell wall
mesh like
comprised of peptidoglycan
Detection of bacteria in clinical samples - microscopy
Morphology
Gram stain
Detection of bacteria in clinical samples - detection of bacterial antigens
H antigen
K antigen
O antigen (LPS)
capsule
Detection of bacteria in clinical samples - Detection of bacterial nucleic acid
PCR
Sequencing
Detection of bacteria in clinical samples - Culture
Metabolic properties
Biomechanical tests
Detection of bacteria in clinical samples - Detection of antibody response to bacteria
ELISA
Western blot
Immunostaining
Taxonomy/Classification
Binomial according to Linnean scheme (genus species)
According to fundamental features
By nucleic acid analysis
Taxonomy/Classification - according to fundamental features like what
Visible features - shape, spore formation, gram rx
Nutrition - aerobic vs. anaerobic, growth temp
End products - production of enzymes or toxins
Surface molecules - unique proteins, sugars, or lipids
Bacterial shapes - Cocci
Circular Coccus = just one Diplococci = two circles Streptococci = single strand of circles Staphylococci = pyramid, grape shape (cluster)
Bacterial shapes - Bacilli
Coccobacillus = oval Bacillus = longer than it is wide
Cytoplasm consists of
Chromosome, mRNA, ribosomes, proteins and metabolites
Cytoplasmic membrane is a __ layer
lipid
Cytoplasmic membrane is responsible for
Electron transport, energy production
many of the functions attributable to organelles in eukaryotes
Cell wall =
peptidoglycan
Appendages =
pili (used for attachment to surfaces)
flagella (movement)
Cell wall - classifications
Two major classifications of bacteria
Gram positive cell wall
Gram negative cell wall
Gram positive cell wall
Thick peptidoglycan layer
Single inner plasma membrane
Gram negative cell wall
Outer membrane Peptidoglycan Periplasmic space Inner plasma membrane Two membranes!
Gram stain - positive
Step 1 - crystal violet
Step 2 - gram iodine
Step 3 - decolorizer (alcohol or acetone)
Step 4 - safranin red
With gram positive it will act right away with the peptidoglycan and when you decolorize it does not come out, so color remains the violet
Gram stain - negative
Step 1 - crystal violet
Step 2 - gram iodine
Step 3 - decolorizer (alcohol or acetone)
Step 4 - safranin red
With gram negative the outer membrane excludes the stain from getting to the peptidoglycan so after you decolorize it gets rid of the violet and when you use the red, the color becomes red
Peptidoglycan layer functions to provide
Protection - physical, mechanical, osmotic, chemical and biological agents Determines cell shape Gram stain (pos vs. neg)
Peptidoglycan is found uniquely on
BACTERIA
DRUG TARGET!
Will attack the bacteria and not the person
Peptidoglycan layer is made of what
Linear chain of alternating sugars cross linked by peptide chains