Why do the hydrogen atoms on the sp3 hybridized carbon in cyclopentadiene have a significantly lower pKa than regular alkyl hydrogens?
By deprotonating the sp3 hydrogen atoms, the entire system becomes aromatic since the lone pair of electrons can now resonate into the pi system, thus stabilizing the conjugate base of cyclopentadiene.
Why does octane have a lower freezing point than decane?
Octane has a lower freezing point than decane because the extra carbon atoms in decane have more London dispersion forces (van der Waals) between them, causing them to be more attracted to each other, and thus freezing first at a higher temperature than octane.
During receptor mediated endocytosis, which subunit of the protein AP2 is attracted to the ligand-bound receptor on the exterior of the cell membrane?
The mu subunit is attracted to the ligand bound receptor.