$5.$ Two different solutions, A and B$,$ are separated by a semipermeable membrane. Assume the membrane has a MWCO $($molecular$-$weight cut$-$off$)$ of $100,000$ Da $($Dalton which is the mass of one molecule and is numerically equivalent to the molecular weight, g$/$mol$).$ Any molecules with a molecular weight below the MWCO will pass through; anything larger will not. Solution A consists of albumin $(80$ g$/$L; MW$=69,000$ g$/$mol$)$ and fibrinogen $(40$ g$/$L; MW$=340,000$ g$/$mol$).$ Solution B consists of albumin $(10$ g$/$L$),$ globulins $(50$ g$/$L; MW$=150,000),$ and fibrinogen $(20$ g$/$L$).$ Assume the solvents for both solutions are water. If the hydrodynamic pressure of solution A is $700$ mmHg$,($A$)$ determine the hydrodynamic pressure of solution B so that there is a net$-$zero flow of water across the membrane. $($B$)$ If the membrane MWCO is lowered to $50$ kDa, determine the hydrodynamic pressure of solution B to maintain a net$-$zero flow of water across the membrane $($assume the hydrodynamic pressure of A is still the same$).$ Assume for both cases that the temperature of the entire system is at $37$oC$.($Ans: A$=705\mathrm{.}3$ mmHg$)$