Question

1)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.


2)Lactose (MW:342 amu) makes up the vast majority of the carbohydrate. Calculate the molarity of lactose in buttermilk and compare it to that of protein.

Answer 1

1. avg molar mass = 110 x 399 = 33,000.
mols protein = grams/molar mass. You know grams and molar mass, solve for mols.

M = mols/L. You know mols and L, solve for M.


2. See #1.

Answer 2

.001151

Answer 3

I .001151 correct? I ended up with 2.72

Answer 4

1.15

Answer 5

Thank you!!

Answer 6

#2 is the same as #1
just it is 12 g
and it is molar mass of 342
so it will be 0.148

Answer 7

do you have to convert the 9grams to liters in order to answer the first question for the protein amount? i

Answer 8

The answer is 0.148.

I got the answer wrong with above,andthey told me this was.

Answer 9

1) 6.52 *10^20 (Trust me on this one)

2) No idea :(