Digestion of Lipids

[liveonearth]

What enzyme in the mouth begins lipid digestion?
lingual lipase

What can lingual lipase digest?
TGs-->monoglycerides, and FFA

What enzyme in infants turns milk into paracasein?
rennin aka chymosin

What cells make rennin in infants?
gastric chief cells

What enzyme then digests the paracasein?
pepsin

What adult gastric enzyme hydrolyzes TGs, short and medium chain fatty acids?
gastric lipase

Where do the hydrolyzed fats go from the stomach?
into the portal circulation

What causes micelle formation in the intestine?
bile
emulsifies

What happens to the micelles?
they are absorbed into intestinal cells where they are
re-esterified and packaged into chylomicrons
then exocytosed into lymph system

What hydrolyzes cholysteryl esters to free cholesterol???
cholesterol esterase

What enzymes attacks phospholipids to produce FFA, glycerol, choline (bases) and phosphoric acid?
phospholipase
remember phospholipase A is the one that gets fatty acids out of membranes

Where do the non-lingual lipases come from?
pancreas

Comments

[neptunia67.livejournal.com]

I've decided to give up my precious granola bars to try to get my triglycerides under control. :-( I'm sad, it was like one of my last weaknesses!

When is (are) the board(s) you are studying for? Is it a series of tests?

[liveonearth.livejournal.com]

Yeah, granola bars definitely turn into TGs. You could keep them but eat only half of one for a snack, instead of a whole one!

I'm studying for basic science boards. It's one full day of multiple guess testing. The material is the first two years of medical school: biochemistry, microbiology, pathology, anatomy and physiology. I can't continue in my program unless I pass these. After two more years I'll take the clinical boards (two days of testing in summer 2011) and the state boards.

Not sure where I'll take the state boards. I might take them here in Oregon, or I might come to AZ to take them. Or maybe NC or VA will have licensure laws by then and I'll go back east. We shall see.

[neptunia67.livejournal.com]

For now, I've given up the whole granola bar, instead having a piece of cheese or small handful of raw almonds along with some raw veggies as my afternoon snack. Seems to be working. I was missing the sweet granola bar badly earlier this week.

What is the date for your science boards?

[liveonearth.livejournal.com]

Yeah, sweets are terribly addicting. The less you eat the less you'll crave it, I think. My exam is August 4.

[newedition.livejournal.com]

Although I'm not on LJ very much, I still enjoy reading your posts. Congratulations on all your school work and good luck on the boards!

[liveonearth.livejournal.com]

Thanks. I'll take all the luck I can get!! Do you have science background? Most non-sciency sorts get nothing from my studious posts.

[newedition.livejournal.com]

Yep, I have an M.S. in cell / molecular biology, so I especially like looking at the biochemical pathways! Too many nutrition books focus on the macro level and never explain the principles biochemically. Many years down the road I'd like to write a book about nutritional biochemistry. There are some available, but I think it would be fun to "trace a meal" from mouth to cell and then back to the whole body system level.

[liveonearth.livejournal.com]

Sounds like the basis for an amazing book. What meal will you trace???

[newedition.livejournal.com]

No idea yet... probably something wild and crazy that has a fantastic balance of protein, carbohydrates, and fats... maybe quinoa with coconut and some funky vegetables. I'll save this post as a bookmark so I remember it in a few years :-)
(And BTW, I am one of those people who really does follow through!)

[liveonearth.livejournal.com]

Mmmmmm. Quinoa with a yellow curry--onions, peas, carrots, you name it. Must have some animal product just so you can teach about heme absorption and vitamin B12 and all. Or maybe have a chapter on what's missing from that meal. I can't wait!!