The cellular membrane is selectively permeable, meaning it does not allow all types of molecules to pass freely. Among the options you provided, the molecule that will pass through the membrane most easily is:
d. N2 (nitrogen gas)
N2 is a small nonpolar gas, which allows it to easily diffuse through the lipid bilayer of the membrane.
In comparison:
- a. H2O (water) can pass through, but it does so less easily than N2 due to its polar nature; it often uses special channels (aquaporins) to facilitate its transport.
- b. Na+ (sodium ion) cannot pass through the membrane easily because it is charged and requires specific ion channels.
- c. C6H12O6 (glucose) is a larger polar molecule that cannot pass through the lipid bilayer without assistance from transport proteins.
So, the order of ease of passage through the membrane from easiest to hardest would generally be: N2 > H2O > C6H12O6 > Na+.
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