Question

how do phytosterols differ from cholesterol?
select the correct answer below:
the hydrocarbon chain on c - 17 of the ring structure is different.
phytosterols have two pentane rings rather than one.
phytosterols have no pentane rings rather than one.
phytosterols do not have carbons 18 and 19 (the methyl groups attached to the rings at carbons 10 and 13).

Explanation:

Phytosterols and cholesterol have similar ring - like structures. The key difference lies in the hydrocarbon chain attached to the C - 17 position of the ring structure. Cholesterol has a specific hydrocarbon chain at this position, while phytosterols have a different one. Phytosterols do have pentane rings (so the options about the number of pentane rings are incorrect), and they do have carbons 18 and 19 (so the option about the absence of these carbons is wrong).

Answer:

The hydrocarbon chain on C - 17 of the ring structure is different.