A researcher is studying the transport of a novel molecule across a synthetic lipid bilayer. They observe that the molecule moves down its concentration gradient without the need for any membrane proteins or energy input. However, the rate of transport is significantly slower than predicted for simple diffusion. Which of the following BEST explains this observation?
The molecule is very large and its size restricts diffusion through the membrane.
The molecule is charged and is repelled by the hydrophobic core of the bilayer.
The molecule is polar and its passage is hindered by the hydrophobic core of the bilayer.
The molecule is binding to a specific receptor on the membrane surface, slowing its diffusion.
Related Questions
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 statement is incorrect?
Proteins in cell membranes can travel within the lipid bilayer
Proteins can remain confined within certain domains of the membrane
Proteins can also undergo flip-flip movements in the lipid bilayer
Many proteins remain completely embedded within the lipid bilayer
Fluid nature of plasma membrane helps in all, except
Cell growth and division
Formation of intercellular junctions
Endocytosis and exocytosis
Providing mechanical strength
