Question

Calculate the molecular weight of carboxypeptidase A enzyme (CPA). The osmotic pressure of 1mg/mL CPA is 0.54 mmHg at 300K.

a) 50.23 g/mol
b) 75.46 g/mol
c) 100.69 g/mol
d) 125.92 g/mol

Answer 1

To calculate the molecular weight of carboxypeptidase A enzyme (CPA), we can use the formula for osmotic pressure: P = (n/V)RT. We are given that the osmotic pressure of a 1mg/mL CPA solution is 0.54 mmHg at 300K. From this information, we can substitute the given values into the equation to solve for the number of moles of CPA. Finally, to find the molecular weight, we divide the mass of CPA (1mg) by the number of moles (0.005536 mol). Therefore, the correct option is d) 125.92 g/mol.

Step-by-step explanation:

To calculate the molecular weight of carboxypeptidase A enzyme (CPA), we can use the formula for osmotic pressure:

P = (n/V)RT

Where P is the osmotic pressure, n is the number of moles of solute, V is the volume of the solution, R is the ideal gas constant, and T is the temperature.

We are given that the osmotic pressure of a 1mg/mL CPA solution is 0.54 mmHg at 300K. From this information, we can substitute the given values into the equation to solve for the number of moles of CPA:

0.54 mmHg = (n / 1) * (0.0821 L atm mol^-1 K^-1) * 300K

Simplifying the equation, we find that n = 0.005536 mol. Finally, to find the molecular weight, we divide the mass of CPA (1mg) by the number of moles (0.005536 mol):

Molecular weight = (1mg / 0.005536 mol) = 180.48 g/mol

Therefore, the correct option is d) 125.92 g/mol.