320Fall2010Homework6 - Cell Biology (BIO 320), Fall 2010,...

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

View Full Document Right Arrow Icon
Cell Biology (BIO 320), Fall 2010, Dr. Bushart Homework 6, for quizzes the week of 10/18 1. Acyl transferase catalyzes the addition of glycerol 3-phosphate to fatty acids in the membrane (the “growth step”). Imagine a cell lacking scramblase activity. Why would the expression of an additional acyl transferase having an ER signal peptide still not allow for even membrane growth in the absence of the scramblase? 2. What ensures that Sar1 and Rab proteins will associate with specific membranes? (In another way to think about it, why won’t Sar1 or Rabs randomly associate with any membrane after activation?) This has to do with the exposure of the amphipathic or hydrophobic region of these monomeric GTPases on conversion to the GTP-bound form. Having these regions exposed to the aqueous environment of the cytosol is not favorable so they will want to associate with membranes as soon as possible. By localizing specific GEFs to specific membranes we can fairly simply ensure that an activated Sar1 or Rab protein will associate with the same membrane the GEF is in. 3.
Background image of page 1

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

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

This note was uploaded on 12/30/2010 for the course BIO 320 taught by Professor Staff during the Spring '08 term at University of Texas at Austin.

Page1 / 2

320Fall2010Homework6 - Cell Biology (BIO 320), Fall 2010,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online