B IO C H E M IS T R Y PE A R L S
Bile salts are the major component of bile and are very efficient
“detergents” when conjugated to amino acids because of the pres-
ence of both polar and nonpolar regions, aiding in fat digestion.
The initial and rate-limiting step of bile acid synthesis is oxidation
of cholesterol to 7a-hydroxycholesterol by a mixed function oxi-
dase from the cytochrome P450 superfamily, cholesterol 7a-
The synthesis of bile salts is under very tight regulatory control,
mainly by a feedback mechanism on cholesterol 7a-hydroxylase,
the rate-limiting enzyme in the synthetic pathway.
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