To break E.coli cells, it was found that operating a high-pressure homogenizer at 60 MPa had the following breaking percentages for each pass. Consider that the resistance of cells to break ()=2.2

number of passes	% released protein
1	50.3
2	75.3
5	96.9
9	99.8

a) Determine the value of k from the rupture kinetics in the homogenizer as a function of the number of passes (N) and the pressure (P).

b) If you want to operate the same equipment at 65 MPa and break 98% of the cells, how many passes are required?

c) What pressure is required to break the same 98% of the cells in just two passes?