Fluid mosaic model Knowledge-Based Download PDF

Questions

1. 1.

   According to the fluid mosaic model, which of the following best explains why peripheral membrane proteins can be released from the plasma membrane using mild salt or pH changes without disrupting the phospholipid bilayer?

   • A) They are covalently linked to the hydrophobic fatty acid tails inside the bilayer.
   • B) They are bound to the membrane surfaces through non-covalent interactions with polar head groups or integral proteins.
   • C) They are embedded within the nonpolar core of the membrane by hydrophobic alpha helices.
   • D) They form transmembrane aqueous channels that span the entirety of both lipid leaflets.
2. 2.

   According to the fluid mosaic model of the plasma membrane, where are the carbohydrate chains of glycoproteins and glycolipids exclusively located?

   • A) On the extracellular leaflet facing the external environment
   • B) On the cytosolic leaflet facing the intracellular fluid
   • C) Distributed symmetrically across both leaflets of the bilayer
   • D) Deep within the central hydrophobic fatty acid core
3. 3.

   According to the fluid mosaic model, which structural feature enables integral transmembrane proteins to remain stably embedded within the phospholipid bilayer?

   • A) Covalent bonds formed between protein side chains and the glycerol backbones of membrane lipids
   • B) Electrostatic interactions between uniformly hydrophilic protein surfaces and the aqueous extracellular fluid
   • C) Hydrophobic interactions between nonpolar amino acid residues and the fatty acid tails in the membrane interior
   • D) Extensive disulfide linkages connecting the protein core directly to cytoplasmic peripheral filaments
4. 4.

   In the fluid mosaic model of animal cell membranes, which component acts as a bidirectional fluidity buffer by restraining phospholipid movement at warm temperatures and preventing tight packing at cold temperatures?

   • A) Peripheral membrane proteins attached to the extracellular matrix
   • B) Cholesterol interspersed within the hydrophobic interior of the bilayer
   • C) Covalent bonds formed between adjacent phospholipid head groups
   • D) Oligosaccharide chains projecting outward from glycolipids
5. 5.

   According to the fluid mosaic model of the cell membrane, which of the following statements correctly describes the arrangement and dynamic behavior of membrane components?

   • A) Phospholipids are linked by rigid covalent bonds that prevent individual lipids from changing position.
   • B) Membrane proteins are anchored permanently in fixed locations along the outer hydrophilic surface.
   • C) Carbohydrate chains are attached exclusively to the cytoplasmic side of the bilayer to stabilize cytosolic enzymes.
   • D) Phospholipids form a dynamic bilayer in which embedded proteins can drift laterally within the plane of the membrane.