Unit 4, Deck 2 Flashcards
(164 cards)
Fatty acids are stored as what?
Triacylglycerols (TAG)
TAGs are linked to glycerol with _______.
ester linkages
Which type of adipose tissue is worse?
visceral
Fatty acids are made accessible by which 3 steps
Degradation, Activation, degradation
What happens in the first degradation step of fatty acid degradation?
TAG is degraded and fatty acids and glycerol are released into the blood.
What happens in the activation step of fatty acid degradation?
The fatty acids are activated and transported to the mitochondria for oxidation.
What happens in the second degradation step of fatty acid degradation?
The fatty acids are degraded to acetyl CoA to be processed by the citric acid cycle
Lipases
hydrolyze lipids to yield fatty acids and glycerol
Which hormones stimulate lipid breakdown?
epinephrine and glucagon
What occurs in lipolysis?
Protein kinase A phosphorylates perilipin and hormone-sensitive lipase, restructuring the lipid droplet and triggering the release of coactivator ATGL. ATGL activation initiates TAG to DAG. HS lipase: DAG to MAG. MAG lipase then forms glycerol and fatty acids.
What happens to the glycerol from lipolysis?
It is converted into DHAP for use in glycolysis or gluconeogenesis
What happens to fatty acids before they are oxidized in fatty acid degradation?
Fatty acids are activated by attaching to coenzyme A in an irreversible reaction with an acyl adenylate intermediate
How does the carnitine enter the mitochondria?
A translocate transports the acyl carnation into the mitochondria and acyltransferase II transfers the fatty acid to CoA and the cycle continues.
What are the four steps of the second degradation?
Oxidation of Beta-carbon, hydration of trans delta squared enoyl CoA, oxidation of L-3 hydroxyacyl CoA, and cleavage of the 3-ketoacyl CoA
What is the picky enzyme in degradation and what does it do?
acyl coA dehydrogenase oxidizes the beta carbon generating trans-delta squared-enoyl CoA and FADH2
TAG –> DAG
ATGL
DAG –> MAG
HP lipase
Mag –> glycerol and fatty acids
MAG lipase
Which degradation steps generate FADH2 and NADH?
FADH2 is produced in the oxidation of the beta carbon.
NADH is produced in the oxidation of L-3-hydroxyacyl CoA.
What is the result of the cleavage of the 3-ketoacyl CoA?
acetyl coA and a fatty acid chain two carbons shorter
How many ATO does the complete oxidation of palmitate yield?
106 ATP
In fatty acid degradation, carbons are removed from the ________ end.
carboxyl
How are monounsaturated fatty acids degraded?
An isomerase converts the double bond allowing beta-oxidation to occur
Odd numbers of unsaturated fatty acids require _________ for degradation.
isomerase