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
Related Questions
Structural lipids of cell membrane are
Simple lipid
Chromolipids
Steroid
Phospholipids
The fluidity of the cell membrane is primarily influenced by the:
Amount of cholesterol present
Saturation level of fatty acid tails in phospholipids
Concentration of peripheral proteins
Presence of glycoproteins
Lipid bilayer is present in
Plasma membrane
Ribosome
Chromosome
Nucleolus
RNA is not found in
Chromosome
Plasmalemma
Nucleolus
Ribosome
The cell membrane is best described as:
Fully permeable
Impermeable
Selectively permeable
Rigid and unchanging
A widely accepted, improved model of cell membrane is
Fluid mosaic model
Robertson’s model
Danielli and Davson’s mod
Unit membrane model
Most common type of lipids found in plasma membrane is A and they show B__ movement with in the plasma membrane. Choose the most appropriate option to fill A and B.
phospholipids; lateral
glycolipids; transverse
cholesterol; rotational
proteins; flip-flop
Plasma membrane helps in
Transportation of only water in and out of cell
Protein synthesis
Osmoregulation
Nucleic acid synthesis
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.
The process by which a cell engulfs large particles or even other cells is called:
Pinocytosis
Exocytosis
Osmosis
Phagocytosis
