Eating Habits - third set Flashcards
(109 cards)
molecular patterns are expressed on..
pathogens and nonpathogens
plasma membrane (gram -) where and what it’s made of
is thin structure lies inside the cell wall, encloses cytoplasm defines the external boundary of cell. made of phospholipids, proteins, and glycoproteins.
Plasma membrane has dynamic role
acts as selective barrier; monitors flow in both direction. ATP/energy demands constant, appropriate internal environment
membrane structure…
best explained by the Fluid Mosaic model. Membrane resembles a sea of lipids with an mosaic of embedded proteins and attached sugar molecules
Lipids (physio)
arranged as bilayer, composed mainly of phospholipids
proteins
are in motion laterally: grouped into 2 classes, Integral and Peripheral proteins
Cholera ToxR : Transmembrane protein ( Biosensor) (parasite swimming)
Allows for rapid sensing and activation of pathogenic functions ToxR
is able to detect acidity and high temps ( signs of host digestive system)
NH2 part reaches cytoplasm
- NH2 terminal domain binds to DNA sequence as a transcriptional activator in turn, activates cholera toxin gene expression as well as other virulence factors
transport system (small cars)
mechanism that facilitates small molecules to enter cell across the normally impermeable membrane
role of transport system
A. To bring in nutrients B. Expel waste products and substances harmful to the cell (efflux) C. Secretion
i. secretion of selective protein molecules which are structural components (like porins proteins of gram negative cells - made in cells) ii. toxins which are virulence factors iii. secretion of enzymes (ex. exoenzymes like amylase) - breaks down large substances for absorption
Transport process is..(PCCT)
PCCT
the functional outcome of activity of channel proteins / transport proteins / carrier protein / permeases
bacterial cell anatomy
AACE
cell envelope, appendages, cytoplasm, accessory structures
External structures
includes cell envelope and appendages
appendages
PEFF
flagella, fimbriae, pili and endoflagella
Flagella (spins..)
spins, forward, uses energy
2/3 energy used for flagella . long, semi rigid and filamentous appendage, aids in motility acts as a spinning motor, propels cell in forward direction flagella motility involves expenditure of cellular energy.
Flagella has 3 basic parts
Filament, hook and basal body
flagella arrangement - names (lamp)
monotrichous, peritrichous, amphitrichous, and lophotrichous
Monotrichous
single polar flagella, Ex: Pseudomonas aeroginosa
Peritrichous
flagella distributed over entire surface, Ex: E. coli
Amphitrichous (spiral voltans)
tuft of flagella at each end of cell Ex: Spirillum volutans
Lophotrichous
two or more flagella at one pole of cell, Ex: Helicobacter pylorii, helps bacteria to cross the mucosal coating of the intestinal epithelium
Favorable stimulus
positive taxis
Unfavorable stimulus (NY)
negative taxis
Attractant and Repellent (runner)
Attractant: more runs of longer duration and less tumbles Repellent: more tumbles
Pili (pill)
F pili - shorter than flagella, 1- 10 per cell, always evolves
Pili (sing pilus) - also called sex pili or F pili or conjugation pili; shorter than flagella - usually 1- 10 sex pili per cells - aids in joining cells of opposite mating types during conjugation process - is one of the methods of genetic exchange of genetic material between bacterial cells. no sexual reproduction. always evolves due to exchange of genetic material