Question

The human blood cell is an enucleated (no nucleus) and flattened cell that lacks intracellular organelles but provides essential functions such as oxygen transport. In this cell, the ratio for proteins mass to phospholipids is 2: Assuming that the mass of the average membrane protein is 50 kilodalton compared to phospholipids (mass= 1000 daltons), approx. how many lipid molecules (i.e. phospholipids + cholesterol) are present for each protein molecule?

The answer key says: 100. Please explain and show work.

Answer 1

The mass of the average membrane protein = 50 kDa
The mass of the average membrane phospholipid = 1000 Da = 1 kDa

The ratio of proteins mass to phospholipids = 2
i.e. the protein mass is twice the lipid mass
However, the average protein molecular weight is 50 times greater than the average molecular weight of a lipid.

So, the ratio between the number of protein molecules to lipid molecules = 1:100

Explanation:
Let us assume (Since the ratio between proteins to lipid is 2)
2 protein molecules = 20 X 50 = 100 kDa

For how many lipid molecules represent 100 kDa
= 1 X 100
= 100 molecules

Please provide a POSITIVE RATING. Thank you