[Campbell Biology P.177] Based on the 'WHAT IF?' scenario in Figure 7.4, if the proteins did... | Practice Question

Based on the 'WHAT IF?' scenario in Figure 7.4, if the proteins did not mix in the hybrid cell even after many hours, which of the following is a valid alternative explanation other than proteins not moving freely within the membrane?

  • A: The membrane itself was rigid and prevented movement.
  • B: The proteins were actively transported out of the membrane.
  • C: The proteins were held immobile by attachment to structures like the cytoskeleton or extracellular matrix.
  • D: The experimental temperature was too high, solidifying the membrane.

Explanation

The text explicitly states: 'Many membrane proteins seem to be held immobile by their attachment to the cytoskeleton or to the extracellular matrix.' This provides a specific alternative explanation for a lack of protein mixing, even if the membrane itself is fluid.