University:
York University
Course:
BIOL 2020 | Biochemistry
Academic year:

2023
Views:

356

Pages:

2
Author:

Nick T.

Lipid Metabolism Lipids in our diet are mainly triacylglycerols "triglycerides" Triglycerides are made from 3 fatty acids attached to a glycerol backbone Digestion of Triglycerides • Initially, Triglycerides are separated into small droplets by churning action in stomach • in the small intestine, bile acids and pancreatic lipases hydrolyze fats to free fatty acids and mono- or diglycerides • Glycerol and some small fatty acids are soluble enough to be transported in the bloodstream • Must be carried by serum albumin During digestion triacylglycerols are broken into their Fats are nonpolar "will not dissolve in water" Fatty acids can be stored in adipose tissue Fatty acids can be oxidized for energy through β-oxidation pathway Bile • Contains Bile acid, cholesterol, phospholipids "Bile acids are synthesized in the liver from cholesterol" "Bile acids act as emulsifying agents" to break apart fat droplets "Bile acids use their hydrophilic/hydrophobic regions to emulsify the lipid droplets so they can be acted on by pancreatic lipases" The small intestine Digestion Bile acids are Synthesized by Liver & Stored in Gall Bladder Sometimes, unmodified Cholesterol is deposited in Gall Bladder Cholesterol can accumulate to form a Gallstone Pancreatic Lipases in intestine partially hydrolyzes the emulsified triglycerides Producing mono- & diglycerides, fatty acids & a Small amount of glycerol Lipid Transport Lipid different Sources metabolism from three the diet Storage in adipose tissue Synthesis in liver Triglycerides & Cholesterol "enter blood from diet "Carried by Lipoproteins Fatty Acids "enter bloodstream from the diet or "released from adipose tissue Triglycerides + Cholesterol "Transported by binding to Serum Albumin "enter blood from diet from Synthesis in Liver "Carried by Lipoproteins Lipoproteins "Carrier molecule Micelle "Consist of: phospholipids on Surface Protein around Surface Cholesterol & cholesterol ester inside Triglyceride inside "Different Lipoproteins are Classified by density amount of protein All lipids must be transported through the bloodstream by a Carrier System