2. Objectives Know the common names and structures of
thefollowing fatty acids: C16, C16:1 C18, C18:1, C18:2, C18:3 C20:4
Understand the relationship between fatty acid chainlength,
unsaturation and melting point. Recognize a TAG, MAG, and DAG
(triacylglycerol,monoacylglycerol, diacylglycerol). Recognize a
phospholipid. You will not need to beable to differentiate among
the different kinds ofphospholipids. 3. What are the sites of
action and products of thephospholipases A1, A2, C, and D? Define
amphipathic (amphiphilic means the samething) (see textbook). What
are the main lipid components of the averagediet? Understand how
the actions of pancreatic lipase,phospholipase and bile acids (same
as bile salts forour purpose) contribute to the digestion
andabsorption of lipid. What happens to the absorbed products of
dietarylipid inside the intestinal cell? Know the basiccomposition
of chylomicrons. Why is a special, complicated mechanism
oftransporting TAGs and cholesterol in the bloodnecessary? What is
this mechanism? 4. Major Macromolecules Carbohydrates Proteins
Nucleic Acids Lipids 5. Fig 9.1 Structural relationshipsof major
lipid classesSignalsEnergyStructure 6. Most Important Lipids:My
Choice Fatty Acids oxidized for energy building blocks for TAGS and
PL precursors to hormones - Eicosenoids Triacylglycerols - TAGS
storage form of fatty acids which are used forenergy Phospholipids
PLs For membranes Cholesterol 7. This is a fatty acid.Amphipathic
contains bothpolar and nonpolar partsEven Number of carbonsMelting
Pointchain lengthsaturation (=)Nomanclature: C1, , , Figure 9-2p.
266 8. Table 9.1Note:oleate = oleic acidstearate = stearic acid 9.
Saturated vsUnsaturatedFatty AcidsC18 stearateC18:1 oleateC18:3
linolenateMP = 70 MP = -17MP = 13 10. Triacylglycerols: a Family
withMany MembersNote these are very hydrophobic!!!More so than the
fatty acids fromwhich they are madeEnergy Storage 11.
Glycerolphos-pholipidsAmphipathic!!!MembraneComponents 12. Fig 9.9
Phospholipases hydrolyzephospholipids PLase A1 or A2 gives a
lysophospholipid (lacking a fatty acid) PLase C gives a
diacylglycerol PLase D gives a phosphatidate 13. Other Classes of
Lipids Lipids Important in Membrane Structure Sphingolipids (Fatty
acids andCarbohydrates) Steroids, especially cholesterol
Specialized functions Waxes Prostaglandins 14. Lipid
MetabolismChapter 16 15. Chapter 16Fatty Acids oxidized for energy
building blocks for TAGS and PL precursors to hormones -
EicosenoidsTriacylglycerols - TAGS storage form of fatty acids
which areused for energy 16. Composition of Lipid in the Diet90%
TAGsPLsCholesterol 17. Digestion and Absorption ofDietary LipidsWe
have a problem. Think oil and water or cutting a cow froma herdHow
do we get from large fat globulesto small molecules which can
beabsorbed across the intestinal cell? 18. Break the hydrophobic
TAGs down to amonoacylglycerol + 2 fatty acidsBreak Phospholipids
down tolysophospholipid and a fatty acidCoat the particles with
amphipathicmolecules (bile salts or bile acids) to makemicelles
hydrophobic part meshes with the lipid hydrophilic part presents to
the watercompartment 19. Fig 16.2 Action of pancreaticlipase 20.
Fig 16.3 Dietary phospholipids aredegraded by phospholipases 21.
Fig 16.1 Bile salts are amphipathic derivatives ofcholesterol and
amino acids. Taurocholate and glycocholate (cholesterol
derivatives) are themost abundant bile salts Amphipathic:
hydrophilic (blue), hydrophobic (black)Synthesized in LiverStored
in gall bladderSecreted into intestineForms micelles 22. Absorbed
from MicellesMonoacylglycerolFree fatty
acidsLysophospholipidsCholesterol 23. In the Intestinal
Cellmonoacylglycerol + 2 fatty acids-->TAGscholesterol + fatty
acid --> cholesterolesterlysophospholipid + fatty acid -->
PLapolipoprotein BAnd we have a special kind oflipoprotein called a
chylomicron totransport lipids around the body 24. Why Do We Need
LipoproteinParticles to Transport Lipid?Solubility of cholesterol
as an example of functionalimportance of lipoprotein particles.0.2
mg/dL in water at 250.150 200 mg/dL in plasma30% free70%
esterifiedIn Bile: Bile salts and phosphatidyl- cholinemaintain
cholesterol in solution.390 mg/d: in bile96% free4% esterified 25.
Fig 16.5 Structure of a lipoprotein 26. Fig 16.6 Summary of
lipoproteinmetabolismLipoprotein Lipase 27. Major Classes of
LipoproteinParticles
