Bacteria Structure and Function Flashcards
What are features of bacteria that distinguish them from eukaryotes?
Bacteria:
- have cell wall
- lack organelles
- DNA not packaged into histones
- can intiate multiple cell cycle events in a single cell (why they grow so fast)
- divide by binary fission
What are unique features of bacteria that the immune system can sense?
- pathogen associated molecular patterns / microbial associated molecular patterns (PAMPs/ MAMPs) i.e. LPS, peptidoglycan, flagellin
- cell surface receptors/intracellular receptors (TLRs, NOD receptors)
Where is MyD88 involved in?
TLR pathways!
Gram positive vs gram negative (outer cell wall stuff)
gram positive - single membrane surrounded by thick cell wall
gram negative - thin cell wall sandwiched between thin cell membranes
What attaches to NAM ( n-acetyl muramic acid in peptidoglycan?)
muramyl peptide (3-5 AAs in length). Critical to action of vancomycin
Which component prevalent in gram negative bacteria protects cell, has modifiable lipid A moiety, and functions as an endotoxin?
lipopolysaccharide!
What component allows bacteria to move towards food sources and away from stress?
Flagellin
What component is a ligand for the TLR5 receptor?
flagellin
What component is a ligand for TLR4 receptor?
lipopolysaccharide
What are some common molecular targets for antibiotics in bacteria?
ribosomes, RNA synthesis, DNA gyrase, cell wall, folate metabolism
Why can antibiotics have toxicity?
Endosymbiotic theory.
antibiotics can target mitochondrial function, esp mitochondrial ribosomes
microbial community
collection of microbes in a defined area (soil, human body, water)
microbiota
microbial communities associated with a host (e.g. humans) don’t confuse with microFLORA
microbiome
collection of microbial GENES in a microbial community
pan genome
set of genes found in a particular bacterial species
