pancreatic β-cell calculation

[sweety_girl]

I don't know how to answer this question.. can anyone help?


A pancreatic β-cell that is cuboidal in shape (10 μm unit length) produces 1 million molecules of
insulin (molecular weight = 5600 daltons) that are stored in dense core secretory granules, each
approximately 300 nm in diameter. Calculate the following:

I) If the insulin-containing granules occupy 10% of the cell volume, how many granules are present
in each cell ?

II) After an extensive chocolate binge, if a quarter of the insulin-containing vesicles fuse with the
plasma membrane releasing their contents, what is the percentage change in surface area for a cell?

III) What is the molar concentration of insulin in each secretory granule?

[canalon]

1) volume of cell*10% divided by volume of a granule
2)(Number of vesicle*surface of vesicle*25%)*100/surface of the cell
3) volume of a granule/number of moles of insulin

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