20 Lipids - TAG and FA Metabolism

20 Lipids - TAG and FA Metabolism - TAG synthesis TAG and...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
TAG synthesis TAG and Fatty Acids catabolism HNFE 3025 Fall 2009
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
First step of fatty acid metabolism Methods of entry: Passive diffusion Occurs with concentration gradient Contributes minimally to cellular influx of fatty acids Fatty acid transporters Fatty acid translocase/CD36 (A.K.A., FAT/CD36) Will translocate to cellular membrane much like GLUT4 » Insulin responsive Is present on mitochondrial membrane and is important for fatty acid entry into mitochondria Fatty acid entry into cell 2
Background image of page 2
Methods of entry cont.d Fatty acid transporters Fatty acid binding protein (FABP) Membrane isoform Cytosolic isoform Fatty acid transport protein (FATP) Also thought to have acyl-CoA synthetase activity » What does this mean? Lipoprotein receptors LDL receptor Chylomicron remnant receptor Specific to what tissue? Fatty acid entry into cell 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fatty Acid Transport Both FAT/CD36 protein content and gene  expression tend to be higher in women A high fat diet increases both FAT/CD36  and IMTG FAT/CD36 and IMTG compared to lean FAT/CD36 more abundant in ST muscle  fibers than FT fibers. 4
Background image of page 4
Depends on the tissue? Liver Dietary lipids Chylomicron remnants LDLs HDLs Fatty acids (short and medium chain) Extrahepatic tissues (adipose, muscle, pancreas, heart) Chylomicrons VLDLs Albumin bound-FA Where do Fatty Acids Come From? 5
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
VLDL LpL Albumin Acyl-CoA synthetase Lipoprotein Receptor Chylomicrons CD36 LpL VLDL FABPpm Fatty acid entry in to cell Triacylglycerol Synthesis Mitochondria Oxidation FABPc CD36 FATP/Acyl-CoA synthetase
Background image of page 6
Fatty acid activation: Acyl-CoA Synthetase Activation step of fatty acids by attachment of  CoA Up to 5-6 isoforms located at ER (SR in  muscle) and outer mitochondrial membrane Specific to chain length and destination to  storage or oxidation Dependent on ATP  Fatty Acid + ATP + Coenzyme A ---> Fatty Acyl-CoA + Pyrophosphate +  AMP + H + 7
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 5-21, p. 158 8
Background image of page 8
VLDL Chylomicrons Albumin LPL LPL CD36 Mitochondrial β-oxidation and respiration ACS ACS GPAT AGPAT GPAT AGPAT DGAT PAP1 Cellular fatty acid metabolism ER or SR
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Know as esterification Occurs in Adipose tissue Liver Skeletal muscle (intramuscular TAG, IMTG) Heart Pancreas Precursors 1 Glycerol 3 Fatty acids as fatty acyl CoA derivatives CoA attached to fatty acids at expense of ATP What enzyme catalyzes this reaction? Triglyceride Synthesis 10
Background image of page 10
Glucose Glucose- 6-phosphate Fructose- 6-phosphate Fructose- 1, 6-bisphosphate Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate Hexokinase Phosphoglucose isomerase Phospho fructokinase Aldolase Triose phosphate somerase ATP ATP ADP ADP Glycerol-3- phosphate Where does glycerol come from? Derived from partial breakdown
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/23/2010 for the course HNFE 3025 taught by Professor Mwhulver during the Spring '10 term at Virginia Tech.

Page1 / 43

20 Lipids - TAG and FA Metabolism - TAG synthesis TAG and...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online