IMP biosynthetic genes constitute the pur operon and are involved in Purines synthesis. Bacterial strain used for this 

#Question id: 2149

#Section 2: General Biology

A ligand-gated ion channel (such as the nicotinic acetylcholine receptor) is:

#Question id: 2150

#Section 2: General Biology

Which of the following increase(s) membrane fluidity?

#Question id: 2151

#Section 2: General Biology

Which of the following statement(s) is (are) true of transmembrane proteins?

a. All contain a hydrophobic α helix.

b. Some serve as membrane attachment sites for peripheral membrane proteins.

c. Some contain more than one membrane-spanning domain.

d. All are asymmetrically oriented in the lipid bilayer.

#Question id: 2152

#Section 2: General Biology

Precursors of membrane phospholipids are

a. soluble in the cytosol.                    

b. incorporated into biosynthetic intermediates.

c. sometimes complexed with fatty-acid-binding proteins.

d. stored in glycerolosomes.

e. sometimes activated by conjugation with CDP.

#Question id: 2153

#Section 2: General Biology

Membrane phospholipids include

a. cholesterol.            

b. plasmologens.        

c. sphingolipids.         

d. triglycerides.                      

e. bile acids.

#Question id: 2154

#Section 2: General Biology

Membrane lipids are distributed appropriately between the two leaflets of a given membrane by

a. dockases.    

b. trumpases.              

c. fatty acid desaturases.        

d. flippases.    

e. transmembrane tunnelases.