Cell The Unit Of Life Question 52
Question: According to widely accepted “Fluid mosaic model” cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect [CBSE PMT 2005]
Options:
A) Proteins in cell membranes can travel with in the lipid bilayer
B) Proteins can also undergo flip-flap movements in the lipid bilayer
C) Proteins can remain confined within certain domains of the membrane
D) Many proteins remain completely embedded within the lipid bilayer
Show Answer
Answer:
Correct Answer: B
Solution:
There are many different proteins embedded in the membrane.
Except for flip flop movements rest occurs.
Choice (a) is amply demonstrated when the travelling proteins aggregate at sites of endocytosis.
Choice (c) type of proteins can be enzymes which are confined to cetrain domains (for e.g., present only on cell surface) choice (d) types are non-trasmembrane proteins.
BETA
