Nature of Infection Flashcards
what is size of prokaryotes?
0.5-10 micrometres
what is size of eukaryotes?
5-50 micrometres
Are prokaryotes and eukaryotes single or multi cellular ?
prokaryotes are often single celled and eukaryotes are multi-cellular
what is speed of cell cycle in eukaryotes & prokaryotes (comparitively)?
prokaryote have rapid cell cycle and eukaryotes have mitosis/meiosis
what is cell structure of eukaryotes?
-cell membrane
-nucleus
-centriole/centrosome
-nucleolus/ribsosomes
-ER
-cytosol
-mitochondria
-golgi
-cytoskeleton
-secretory vesicles (lysosomes)
what is cell structure of prokaryotes?
-plasma membrane
-cell wall (peptidoglycan)
-nucleoid (DNA & associated proteins)
-ribosomes
-cytoplasm
-capsule, flagellar & pili
what is the cytoplasmic membrane of prokaryotes?
-lipid bilayer
-retains cytoplasm
-selective barrier
-transport
-reaction surface e.g. respiration, lipid synthesis
*important for import/export
what is aerobic respiration process of energy productions? (basic)
- electrons released from high energy compounds in cytoplasm
- reach membrane and passed through series of electron acceptors
- as a consequence protons passed outside membrane producing a +ve charge and proton gradient across membrane that is used by ATP synthase for energy
what are the 2 forms of energy production in prokaryotes?
aerobic and anaerobic
what is a nucleoid?
- DNA & associated proteins
not the same as nucleus = no membrane or defined locations
what are chromosomes like in prokaryotes?
- chromosomes are single circular molecule
-organised by gyrases
-extra chromosomal replicons often exist e.g. plasmids
what is primitive DNA segregation machinery?
in prokaryotes - DNA is circular and has enzymes that can be targeted with drugs
how are our ribosomes different to prokaryote ribosomes?
similair in that they turn mRNA into peptides but different in that there is a whole bunch of enzymes that can be targeted by drugs
what is structure of peptidoglycan cell wall?
repeated sugar chains = NAM NAG
peptide side bridges = 5 amino acids
(sugar cage cross-linked by amino acid bridges) - not in one flat dimension, it actually spirals so different places of crosslinking
what type of environment is peptidoglycan wall more common?
cells that live in variable environments as peptidoglycan can cope with higher pressure
what are components of gram +ve cell wall?
-rigid layer
-barrier
-repeated polysaccharide structure
-target of penicillin
-Gram +ve = multi layer & often secondary polymer
what are components of gram -ve cell wall?
-rigid layer
-barrier
-repeated polysaccharide structure
-target of penicillin
-Gram -ve
= outer membrane
= often decorated with LPS (Lipopolysaccharides = important outer membrane components of gram-negative bacteria.)
= periplasmic space (space between inner &outer membrane)
what are lipopolysaccharides (LPS)?
=they’re also referred to as endotoxin & linked to sepsis/septic shock
- found almost completely covering outer membrane of Gram -ve as outer membrane asymmetric
what increases the surface area of prokaryotes?
flagella & fimbriae, as they can attach to far away bacterial cells and allow horizontal gene transfer
what do flagella and fimbriae allow?
flagella allows movement (long)
fimbriae are shorter and allow attachement
what are pili?
a slightly longer fimbriae (not as long as flagella)
what antiobiotic targets DNA gyrases?
fluoroquinolones
what structure is linked to antiobiotic uptake and inflammation?
outer membrane & LPS (gram -ve)
what structure is linked to sonication & ethanol?
cytoplasmic or plasma mebrane - they get damaged by sonication & ethanol
