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Kaplan Qbank USMLE



Author4 Posts
  #1

I have some questions that i am not sure....can u guys help me out ?

1. Which of the following is the best phrase to describe the modern view of membrane
structure?
a. Membranes are lipid-lipid bilayers.
b. Membranes are lipid-lipid bilayers with associated proteins.
c. Membranes are composed solely of lipids and proteins.
d. Membranes are a fluid mosaic of lipids and proteins.
e. Membranes are found only in eucaryotic cells.

2. Proteins in biological membranes participate in all of the following activities, except:
a. Transport
b. Catalytic activity
c. Blood clotting
d. Receptor sites
e. All of these are correct.

3. Transport across a membrane can involve all the following, except:
a. Passive transport
b. Facilitated transport or diffusion.
c. Protein channels
d. Passive transport, facilitated transport or diffusion.
e. All of these are correct.

4. The mechanism of membrane transport may involve the following:
a. ATP hydrolysis.
b. Conformation change of membrane proteins.
c. Phosphorylation or dephosphorylation of membrane proteins.
d. ATP hydrolysis and conformation change of membrane proteins.
e. All of these are correct.

5. Vitamin E has all of the following properties, except:
a. It is an antioxidant.
b. It can be made in the sunshine.
c. It is essential for at least some mammal's fertility.
d. It is often a component of membranes.
e. All of these describe vitamin E.


6. A bacterial cell wall is composed of:
a. One type of polysaccharide and 2 different types of oligopeptides, which are
cross-linked.
b. One type of polysaccharide and 1 type of oligopeptide, arranged in 2 different directions.
c. One type of polysaccharide and an oligopeptide covalently bonded to the cell membrane.
d. Two different polysaccharides and 1 type of oligopeptide, which are cross-linked.
e. More than one of these statements is true.

  #2

1.b
2. e
3.e
4. d
5 a
6. dunno

Edited by Jackofknives on 10/27/07 - 01:03 AM

___________________
There are many things in this world that can’t be changed no matter how hard you try. That’s why you must not hesitate when the time comes where you have to give it all you’ve got.

  #3

hey jok... for 5 ans is b

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srama nee ayutham aithe vijayam nee banisa avuthundi

  #4

oh oops

___________________
There are many things in this world that can’t be changed no matter how hard you try. That’s why you must not hesitate when the time comes where you have to give it all you’ve got.







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