what are Sterols / Steroids? structure and function with example

Steroids:
is the third major class of lipids in the steroids which are organic compound
with four ring arranged in specific molecular configuration.

In this structure three cyclohexane ring A B C are
connected in the same way as in phenanthrene a fused cyclopentane ring D is
also present. Examples include cholesterol, the sex hormones estradiol and
testosterone.

Sterol:
are
the sub group of steroids which have alcohol also know is steroids alcohol and
important class of organic molecule.

In structure 3 cyclohexane ring and 1 cyclopentane
ring.

They are naturally present in plants animal and fungi
and also produce by some bacteria.

Sterols of plants are called phytosterols and sterols
of animals are called zoosterols. Most important sterol in Animals
is cholesterol.

Cholesterol:
the
most abundant steroid in the human body and the most important is cholesterols.
Cholesterol is 27 carbon compound and a hydroxyl group on carbon number 3. It
is quit solid. Cholesterol serve as a plasma membrane component in all animal
cell such is red blood cell. It second function is to serve as a raw material
for the synthesis of other steroids such as the sex and adrenocorticoid
hormones and bile salts.

Phytosterols example are Ergosterol: this is the chemical composition of ergo sterol.
they   are found in the cell
membrane of fungi and protozoa. The same function that cholesterol serve in
animal cell.