Lipids_and_Lipoproteins

Lipids_and_Lipoproteins - Lipids and Lipoproteins Roger L....

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

View Full Document Right Arrow Icon
Lipids and Lipoproteins Roger L. Bertholf, Ph.D. Associate Professor of Pathology Director of Clinical Chemistry & Toxicology
Background image of page 1

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

View Full DocumentRight Arrow Icon
Classification of lipids Fatty acids (palmitic, linoleic, etc.) Glycerol esters (triglycerides) Sterols (cholesterol, hormones, vitamin D) Terpenes (vitamins A, E, K) Sphingosine derivatives (sphingomyelin)
Background image of page 2
Fatty acids Even-numbered fatty acids predominate The most common saturated fatty acids are palmitic (16:0) and stearic (18:0), but unsaturated fatty acids are more common in nature OH O Lauric acid (C 12 , 12:0, n -dodecanoic acid) α β ϖ
Background image of page 3

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

View Full DocumentRight Arrow Icon
Unsaturated fatty acids Double bonds in fatty acids are nearly always cis OH O Palmitoleic acid (16:1 9 , 9-hexadecanoic acid)
Background image of page 4
Essential fatty acids Mammals can synthesize saturated and mono-unsaturated fatty acids. Linoleic (18:2) and linolenic (18:3) fatty acids cannot be synthesized, and therefore must be obtained from the diet (plants). Both are required for the biosynthesis of prostaglandins
Background image of page 5

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

View Full DocumentRight Arrow Icon
Clinical importance of fatty acids Fecal fatty acids are sometimes measured to detect malabsorptive and pancreatic disorders—the test is mostly considered obsolete Serum free fatty acids help distinguish between hyperinsulinemic hypoglycemia (FFA normal) and disorders of fatty acid oxidation (FFA elevated and negative ketones)
Background image of page 6
Glycerol esters (acylglycerols) Triglycerides are the most abundant family of lipids in plant and animal cells, and are major components of the the human diet H C H OH C C H OH H H OH Glycerol H C H O C C H O H H O CO CO CO (CH 2 ) n (CH 2 ) n (CH 2 ) n CH 3 CH 3 CH 3 Triglyceride
Background image of page 7

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

View Full DocumentRight Arrow Icon
Measuring triglycerides (reference method) Triglycerides are extracted into chloroform prior to analysis Triglycerides KOH fatty acids + glycerol Periodate formic acid + formaldehyde chromotropic acid chromogen λ =570 nm
Background image of page 8
Measuring triglycerides (enzymatic method) Triglycerides Glycerol + FFAs Lipase Glycerophosphate + ADP Glycerokinase ATP Dihydroxyacetone + H 2 O 2 Glycerophasphate oxidase Peroxidase Quinoneimine dye λ max 500 nm
Background image of page 9

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

View Full DocumentRight Arrow Icon
Sterols (cholesterol) Sterols are steroid backbones that have a hydroxyl group at position 3 and a branched aliphatic chain of 8 or more carbons at position 17 HO 1 2 3 4 5 6 7 8 9 11 12 10 13 14 15 16 17 A B C D
Background image of page 10
Cholesterol biosynthesis About 2% (approximately 1 g) of total body cholesterol is replenished each day Dietary sources account for less than half Cholesterol is synthesized from Acetyl CoA 90% of in vivo synthesis occurs in the intestine and liver (although all cells have the capability) Absorption of dietary cholesterol appears to have a maximum of approximately 1 g/day
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.

Page1 / 47

Lipids_and_Lipoproteins - Lipids and Lipoproteins Roger L....

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