Bacterial Growth & Physiology Flashcards
Obligate anaerobes
Obligate anaerobes – can only growth in absence of oxygen
Poison
Poison – radicals, superoxide, and H2O2 damage cell, lack antioxidant enzymes
Obligate aerobes
Obligate aerobes – can only growth in presence of oxygen, contain all antioxidant enzymes
Microaerophiles
Microaerophiles – require low percent oxygen
Aerotolerant anaerobes
Aerotolerant anaerobes – do not use oxygen to grow but are not affected
Facultative anaerobes
Facultative anaerobes – use oxygen in present (more efficient) but can live without it
Respiratory Metabolism
Respiration – more efficient, TCA cycle to produce ATP, NADH, and FADH2 in presence of oxygen
Fermentation
Fermentation – glycolysis, pyruvate → ATP in absence of oxygen, recycling of NADH → NAD+
Pentose Phosphate
Pentose phosphate – produces reducing power (NADPH), hexose monophosphate shunt
Iron utilization:
highly insoluble as Fe3+, bound to proteins
Siderophores
– scavenge iron, high affinity
Antiseptic
Antiseptic – used on tissue to reduce microbes
Aseptic
Aseptic – absence of pathogenic microbes
Antibiotic Targets
Targets – cell wall, protein synthesis, RNA/DNA synthesis
Disinfectant
Disinfectant – chemical kills microbes on objects, not sterile
Sterilization
Sterilization – complete killing of all organisms, autoclave
Antibiotic Replication
Replication – DNA polymerase, topoisomerase IV, gyrase (topo II)
Antibiotic Transcription
Transcription – RNA polymerase
Antibiotic Translation
Translation – 30S and 50S rRNA subunits
Biochemical Resistance
Resistance –
Biochemical – enzymatic inactivation of antibiotic, ex: target site change, permeability
Genetic resistance
Genetic – chromosomal mutation or genetic exchange
Penicillin
Penicillin – inhibits cell wall synthesis by binding to PBP, preventing formation of peptidoglycan
Vancomycin
– inhibits cell wall synthesis by binding to D-ala to prevent cross-linking
