Lecture 3+4+DLA Flashcards
Dysbiosis
loss of diversity of the microbiota which leads to issues like necrotizing enterocolitis or chronic inflammatory disorders of the GI tract
microbiome characteristics
immune modulation
influence metabolism
produce inhibiting antimicrobial substances (bacteriocins or lower pH)
limit availability to pathogens
prevent binding of pathogens to receptors
Gram + bacteria?
have a thicker wall of peptidoglycan and will stain purple
Gram - bacteria?
have a thinner wall of peptidoglycan + an outer membrane and will stain pink
what makes up peptidoglycan?
composed of two covalently bonded sugars with the two amino acids NAM and NAG
NAM = n-acetylmuramic acid NAG = n- acetylglucosamine
Bacitracin
A drug that prevents bactoprenol from shuttling the monomer across the membrane to the periplasmic space
bacteria replicate by synthesizing NAG-NAM monomers in the cytoplasm, thus stopping the replication of bacteria
The role of Transpeptidases and/or Penicillin-Binding Proteins (PBPs)
catalyze the incorporation of the monomer into the adding it to the existing peptidoglycan wall matrix
the target of B-lactam drugs (including penicillin)
PBP’s
this is because PBPs bind to pentapeptide of NAG-NAM monomer and enzymatically remove a peptide to form a covalent bond or bridge, thus adding to the chain
features of gram + bacteria
thick peptidoglycan
teichoic acid
lipoteichoic acid
TA and LA both serve has a scaffold for the peptidoglycan layers and contribute to adhesion and are recognized by phagocytes
features of gram - bacteria
thin peptidoglycan periplasm outer membrane porins lipopolysaccharide
About LPS (lipopolysaccharide)
has three units
O antigen-
outer polysaccharide
helps with attachment
lipid A:
toxic affect
can serve has an endotoxin and lead to sepsis and even septic shock when recognized by innate immune cells
core polysaccharide
range
the diff between the highest and lowest point
finding the IQR
the range of the middle half of a distribution
- put the numbers in order
- find the median
- divide the numbers in half (both above and below the median)
- Find Q1 and Q3
- subtract Q1 from Q3
variance and how to find it
Variance is the average of squared distances from the mean
- find the mean
- subtract mean from each observation and square it
- calculate average of those squared numbers
sample pop… must do n-1
SD and how to find it
smaller vs larger SD
the average distance from the mean
the square root of the variance
must do N-1 for sample pop
smaller SD = narrower graph and more precise
larger SD = wider graph and less precise
