Bile Salts Flashcards
What are bile salts used for?
emulsify dietary lipids
Where are bile salts synthesized and where are they stored?
Synthesized in the liver
Stored in the gallbladder
Rate limiting enzyme in bile salt synthesis ?
7-alpha hydroxylase
Chenochenolic acid and chenille acid are uncojugated bile salts because?
the COO- is free and they have a pa 6-8
What is the pKa of conjugated bile salts close to?
Their pH is closer to 4
Why are conjugate bile salts much better than unconjugated bile salts at a pH of 7 in the intestinal mucosa’s lumen?
Think of the Henderson-Hasselbach equation.
The conjugated bile salts are much better because the exist in a deprotonated form in the pH of ~ whereas noncojugated bile salts exist in a protonated/deprotonated ratio of one which means that 50% are protonated and unable to emulsify fats (not polar enough).
How many times are bile salts recycled and how effective is it ? What happens to the other 5%?
Bile salts about 6 times per day and is 95% effective.
The other 5% is excreted.
What do enzymes in the intestine do to the molecules ?
They make them less soluble and less polar (can’t be reabsorbed)
What is the difference between a primary bile salt and a secondary bile salt?
Secondary bile salts do not have an OH at the 7th carbon
Cholesterol is the essential substrate for which enzyme?
7-alpha-hydroxylase
Mechanism by which the enzyme catalyzing the rate limiting step in bile salt synthesis is regulated.
Feedback inhibit by bile acids
