{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

mcdb100prob_2answers_08W

mcdb100prob_2answers_08W - Name TA Session MCDB 100 Problem...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Name______________________________ TA / Session ______________________________ MCDB 100 Problem Set #2 Jan 15,2008 Due: In class Jan 24, 2008 1. (a) How many phospholipid (PL) molecules, each occupying 0.7nm 2 of surface area, are there in a human red blood cell (RBC) surface membrane? Assume the surface area of an RBC is equivalent to a sphere of ~ 6.7 µ m. Area =S RBC = π d 2 = 3.14x (6.7x 10 3 ) 2 = 1.4 x 10 8 nm 2 N PL = S RBC / S PL = 1.4 x 10 8 nm 2 / 0.7nm 2 = 2x 10 8 molecules 1. (b) Experimental measurements gives about 4x 10 8 molecules per RBC. What does this tell you about the PL organization of the RBC? The number calculated is ½ the experimental value suggesting that the ___ RBC cell membrane is a bilayer _____________________________________ ________________________________________________________________ 2. Many integral membrane proteins are free to move in the plane of the cell membrane. (a) What is the average distance traversed by such a protein in 1 sec? Assume the diffusion coefficient s 10 -8 cm 2 /sec. Ans: <x 2 > =2Dt or x = 2Dt = 2x 10 -8 x1 = 1.4 µ m (b) How long would it take for such a protein to go once around a liver cell assumed to be a 20 µ m sphere? To simplify just compute this for a circumferential path.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern