Flashcards in MCP - Turner - Lipids and Their Metabolism - 2/20 Deck (32)
How are triglycerides stored?
In an anhydrous state
Compared to carbohydrates, fat provides ___ times the metabolic energy per gram of tissue.
What is the ionization state of fatty acids in vivo?
pKa 4.8, ionization state is negative
T/F: Most human fatty acids have an even number of carbons.
How do ionized fatty acids appear in the cell?
They aggregate into micelles.
C14, 0 double bonds, the acid is myristic, the salt is:
C16, __ double bonds, the acid is palmitic, the salt is palmitate.
C16, 1 double bond, the acid is palmitoleic, the salt is:
16:1delta9 (location of double bonds)
___, 0 double bonds, the acid is stearic, the salt is stearate.
C18, 1 double bond, the acid is ____, the salt is oleate
18:1delta9 (location of double bonds)
C18, ___ double bonds, the acid is alpha-linoleic, the salt is linoleiate
18:2delta9, 12 (location of double bonds)
____, 3 double bonds, the acid is linolenic, the salt is linolenate
18:3delta9, 12, 15 (location of double bonds)
C20, 4 double bonds, the acid is arachidonic, the salt is ___.
20:4delta5, 8, 11, 14 (location of double bonds)
Fatty-acid-derived ____ enters the TCA cycle, yielding ATP and heat.
T/F: The brain can use free fatty acids for fuel.
False, BBB prevents fatty acid transport
T/F: Fatty acids can be obtained from the diet or synthesized de novo.
Excess energy is converted to ___ for storage.
What are the three main components of bile?
Bile acids (aka bile salts)
How do dietary triglycerides appear as?
Mostly long chain TGs, in which the esterified fatty acids are long chain fatty acids
Where and by what enzyme are the majority of triglycerides digested?
duodenum and proximal jejunum
The main products of TG digestion are 2-monoacylglycerol (MAG) and NEFA
What are the 3 main causes of steatorrhea?
1. Failure of bile production or blockage of bile flow
2. Exocrine pancreas dysfunction or obstruction or pancreatic duct
3. Failure of uptake into intestinal mucosal cells
In the intestinal cell, ____ is resynthesized from 2-MAG and absorbed long chain fatty acids and then packaged into liprotein particles called chylomicrons that are exported into the lymph.
What is the function of acetyl-CoA synthase (also called thiokinase)?
Acetyl-CoA synthase catalyzes formation of acetyl-CoA derivatives of long chain fatty acid
What is the function of acyltransferases?
Acyltransferases, aslo known as transacylases catalyze the transfer of 2 LCFA moieties to 2-MAG
What are chylomicrons?
For transport into the lymph and blood , water-insolube TG must be packaged into a type of lipoprotein particle, called chylomicrons
What is Apo-B48?
Apo-B48 is the principal protein component of nascent chylomicrons as they are produced in the intestinal mucosa
T/F: Chylomicrons and other lipproteins only transport TGs.
False, other lipids are also transported.
Fatty acids are released from lipoproteins by the action of ____ in the capillary endothelial walls of various tissues, especially muscle and adipose tissue.
Cleavage occurs at all 3 ester bonds
Products are glycerol and NEFA
T/F: Entry of nonesterified long chain fatty acids from the intestinal lumen into the intestinal mucosa is mediated by protein carriers.