DAT bootcamp Bio q

[panmit]

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The structure of plasma membranes is often described as having proteins float on top of a sea of phospholipids. Which of the following matches this description?

• A. Prebiotic soup
• B. Extracellular matrix
• C. Hydrophilic-Hydrophobic model
• D. Fluid mosaic model
• E. Liquid bilayer hypothesis

The answer is Fluid Mosaic Model. I thought that only describes the fluidity of the plasma membrane. I thought the answer would be Extracellular Matrix because they matrix is right on top of the plasma membrane containing proteins such as collagen, etc.

 

[emminent]

ECM is everything beyond glycocalyx and plasma membrane.

 

[Project Pat]

How about eliminating the wrong answers...
A. Prebiotic soup - referring to the "soup" where life originated
B. Extracellular matrix - Extra = outside cellular = cell... so this means the space outside the cell
C. Hydrophilic-Hydrophobic model - referring to how the phospholipid bilayer is organized... hydrophilic heads with hydrophobic tails
D. Fluid mosaic model - Correct, the molecules of the plasma membrane change their positions (fluid movement). check out this video:
E. Liquid bilayer hypothesis - similar to answer C... this is again how the phospholipid bilayer is arranged.

 

[Dotoday]

The question is ambiguous. They do not float on top of the membrane, they are clearly anchored to it. I can see how you thought ECM. You would probably be right.

 

[Member 139582]

haha I got this question wrong and thought the same thing.