Introduction
Cryptosporidium parvum infects what part of the human body?
What is the gastrointestinal tract
Electrophoretic mobilities were converted to zeta potentials using what equation
Smoluchowski equation
The overall decrease in the zeta potential as the KCl concentration is increased can be attributed to what
double-layer compression
An additional repulsive force must be present to explain the low attachment efficiency of the Cryptosporidium oocysts to the quartz substrate in the presence of a monovalent salt (KCl). The authors surmise that this additional repulsive force is ascribed to
electrosteric repulsion
What do we know from Figure 4b
the overall zeta potential of the viable Cryptosporidium after washing off the SDS and EDTA remains unchanged indicating that the SDS and EDTA were effectively removed by our washing technique
The acidic macromolecules impart what with solid surfaces, thus hindering oocyst attachment
What is steric repulsion
the digestion of the oocyst surface macromolecules was performed with what enzyme
proteinase K
According to Figure 1 for the viable oocysts, at what ionic strength was the zeta potential the highest?
110 mM
Previous studies have suggested that the oocyst surface contains anchored what stretching into solution due to electrostatic repulsion between surface ionizable groups distributed along the polypeptide backbone. It has been suggested that the formation of this brush like structure imparts a steric repulsion with the quartz substrate.
glycoproteins
DOUBLE JEOPARDY
Why was Proteinase K chosen (2 reasons)?Proteinase K was chosen because it is a highly aggressive protease, which cleaves peptide bonds at the carboxylic sides of aliphatic, aromatic, or hydrophobic amino acids. Also the overall integrity of the oocyst would remain intact after treatment with this protease.
Oocyst deposition rates and corresponding attachment efficiencies were low in the presence of what monovalent salt
KCl
After digestion of the oocyst surface macromolecules with proteinase K, the sample was run through what to verify their effective removal
high performance liquid chromatograph (HPLC)
According to Figure 2, the highest attachment efficiency occurs at what ionic strength?
117 mM
What have shown the ability to compress the polyelectrolyte layer to varying extents, and subsequently reduce the electrosteric repulsion with solid surfaces
Divalent cations
Removal of the carbohydrates (uncharged moieties) should result in an increase in the what of the oocyst surface
hydrophilic nature
Oocyst deposition rates and corresponding attachment efficiencies were low in the presence of what divalent salt
CaCl2
quartz slides were chemically modified using a 0.2% (v/v) mixture of what compound
(amino-ethylaminomethyl)phenethyltrimethoxysilane
DOUBLE JEOPARDY
Do you trust this data with such a large standard deviation? Why do you think they did not continue to increase the ionic strength until an even higher efficiency was obtained?
uhhhhh
DOUBLE JEOPARDY
A previous found that the attachment of oocysts to biofilms display calcium dependency. Do you have any theories as to why this may be, based on the findings of this paper?Divalent cations have shown the ability to compress the polyelectrolyte layer to varying extents, and subsequently reduce the electrosteric repulsion with solid surfaces
Also fun fact
CTLD (calcium-type lectin domain) containing proteins are calcium-dependent, glycan-binding proteins ubiquitous among both vertebrates and invertebrates
According to Figure 6, the attachment efficiencies continue to remain near unity at ionic strengths of what
100 and 177 mM
What digestive enzymes were used to cleave the surface glycoproteins from the oocyst
Proteinase K
What kind of system was utilized to determine the oocyst deposition kinetics
Radial stagnation point flow system (RSPF)
To explain the low attachment efficiency, even at high ionic strengths, we turn to what theory
DLVO theory of colloidal stability
What is the purpose of Figure 3?
to determine if the surface polymers were effectively removed from the oocyst surface
The results derived from Figure 6 signify that oocyst deposition reached a point of what-limited rate
transport-limited