In the lab, biologists can create a cell surrounded by a phospholipid bilayer me

Question

In the lab, biologists can create a cell surrounded by a phospholipid bilayer membrane that contains no transmembrane proteins. These structures are known as liposomes. There are 5 million phospholipid molecules per square micrometer (µm2) in one layer of a phospholipid bilayer membrane that contains no transmembrane proteins. The external diameter of a typical human cell is 30 µm. How many phospholipid molecules would be in the outer layer of a phospholipid bilayer membrane that surround a liposome with a 30 µm external diameter?

The surface area of a spherical liposome can be calculated as: Surface Area = 4?r2.

Explanation / Answer

Given:

Diameter (d) = 30 µm;

Number of phospholipid per µm2 (n) = 5,000,000 = 5*106

Solution:

Radius (r) = d/2 = 30/2 = 15 µm

Surface area (A) = 4?r2 =4*?*152 = 2827.43 µm2

Number of phopholipid molecules in outer layer of liposome (N) = A*n = 2827.43*5*106 = 1.41*1010

=14.1*109 = 14.1 billion

Number of phopholipid molecules in outer layer of liposome = 1.41*1010 or 14.1 billion

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.