Buttermilk has 9 grams of protein and 12 grams of carbohydrate per cup (237ml). Estimate the concentration in mol/L of protein using the fact that the average protein is 300 amino acids long and the average amino acid has a mass of 110 amu
So the avg molar mass of protein is
300 amino acids x 110 g/amino acid = about 33000.
mols protein = grams/molar mass = about 9/33000 = ?
Then M = mols/L = ?mol from above/0.237L = ?
.0115074798619102
It's actually 0.00115
To estimate the concentration of protein in mol/L, we need to convert the mass of protein (in grams) into moles. Here's how we can do that:
1. Determine the mass of protein in one cup of buttermilk.
Since we know that one cup (237ml) of buttermilk contains 9 grams of protein, the mass of protein is 9 grams.
2. Calculate the number of moles of protein using the molar mass.
The average protein is 300 amino acids long, and each amino acid has a mass of 110 amu (atomic mass unit). So, the molar mass of a protein would be:
molar mass of protein = 110 amu x 300 = 33,000 amu
However, to convert the molar mass from atomic mass unit (amu) to grams per mole (g/mol), we need to divide by Avogadro's number (6.022 × 10^23). This yields:
molar mass of protein = 33,000 amu / (6.022 × 10^23) = 5.48 × 10^-20 g/mol
3. Convert the mass of protein in grams to moles.
Number of moles of protein = mass of protein / molar mass of protein
Number of moles of protein = 9 grams / (5.48 × 10^-20 g/mol)
4. Convert the volume from milliliters to liters.
The volume of buttermilk is given as 237 ml. To convert this to liters, divide by 1000:
Volume of buttermilk in liters = 237 ml / 1000 = 0.237 L
5. Finally, calculate the concentration of protein in mol/L.
Concentration of protein (mol/L) = Number of moles of protein / Volume of buttermilk in liters
Concentration of protein (mol/L) = (9 grams / (5.48 × 10^-20 g/mol)) / 0.237 L
By plugging the numbers into the equation, you can obtain the estimated concentration of protein in mol/L.