1. Agenda Function of Lipids Types of Lipids Structures of fatty acids
Hydrogenation
Nomenclature
Essential fatty acids

2. Functions Long-term ___ storage Support organs Insulation
Fat soluble vitamins A, D, E, K

4. Types Physical Property Chemical Property Fatty acids Triglycerides
Phospholipids
Cholesteryl ester
Vitamins

6. Fatty Acid Structure 1 Chain length (chemical property)
Melting/boiling point (physical property)
Solubility in water (physical property)
Long chain FA – carbons (most naturally occurring FA)
Medium chain FA – 8-12
Short chain FA – shorter than 8

7. Fatty Acid Structure 2 Type of bonds (chem prop)
State/phase at room temperature (phys prop)
Glycerol
“backbone”
Poly-unsaturated fatty acid
Saturated fatty acid
Mono-unsaturated fatty acid

9. Fatty Acid Structure 3 Trans- vs. Cis- fatty acids
State/phase at room temp

11. Review The four major classes of lipids are: fatty acids, ___
The different types of fatty acid are: _____________
The longer the fatty acid chain, the stronger/weaker the intermolecular force, and higher/lower the melting and boiling points.
What is the difference between fat and oil?
What chemical property contributes to the state of lipids?

12. Hydrogenation Hydrogenation: adding hydrogen
double bonds  single bonds
cis double  trans double
purpose: improve texture (liquid to solid) and shelf-life (less likely to oxidize)

13. Hydrogenation

14. Partial Hydrogenation
Rarely found in nature
Fats and oils that may contain a high proportion of trans-fatty acids are:
Margarine
Frying Fats
Shortening

16. Nomenclature α Naming System: 18:3 cis-9, cis-12, cis-15
ω Naming System: omega-3
Common Name: linolenic acid (α-linolenic acid)
How many carbons in length
How many double bonds
Where are the double bonds
Cis or trans double bonds

17. Saturated Fatty Acids = No Double Bonds Stearic AcidH H
Oleic Acid
Monounsaturated Fatty Acids =
One Double Bond H
Elaidic Acid H
Linoleic Acid
Polyunsaturated
Fatty Acids =
More than One
Double Bond
Rumenic Acid

18. Saturated Fatty Acids = No Double Bonds Stearic Acid 18:0H H
Oleic Acid
18:1 cis-9
Monounsaturated Fatty Acids =
One Double Bond H
Elaidic Acid
18:1 trans-9 H
Linoleic Acid
18:2 cis-9 cis-12
Polyunsaturated
Fatty Acids =
More than One
Double Bond
Rumenic Acid
18:2 cis-9, trans-11

19. Nomenclature
Name each of the following by its α and ω names (or draw its molecular structure)
cis9-16:1
cis5, cis8, cis11, cis14-20:4

21. Name These Fatty Acids

22. Properties of Triglycerides
Can you explain the physical properties in terms of the chemical structures of the fatty acids?
Animal foods contribute the majority of dietary SFAs, whereas plant-derived foods supply the majority of PUFAs. MUFAs come from both plant and animal foods. Tropical oils (coconut and palm) contain relatively high amounts of SFAs, and many oily fish have high levels of PUFAs.

23. Does the human body use lipids from our diet as the way they are?
No, lipids are broken down into smaller units (fatty acids & glycerol)
Once broken down and absorbed, then can be restructured/changed into forms the body can use

24. Essential Fatty Acids
α-Linolenic Acid
Linoleic Acid
Omega 3
Omega 6
The body cannot synthesize double bonds in the ω-3 and ω-6 positions
The body uses the essential fatty acids to make nonessential fatty acids (EPA, DHA, ACA) and other lipid-like substances (eicosanoids)

25. Elongation & Desaturation
The body uses the essential fatty acids to make ACA, EPA and DHA by increasing the number of carbon atoms and the number of double bonds

26. EPA & DHA Hormones in the immune and cardiovascular systems
Biological membrane in nerve tissues and retina
Necessary for epithelial cell function
Involved in gene regulation
Docosahexaenoic acid (DHA)
Eicosapentaenoic acid (EPA)

27. Conditionally Essential Fatty Acids
Infants lack the enzymes to make DHA from linoleic and linolenic acids
Conditionally essential nutrients must be supplied to the body only under special conditions, such as stress, illness, aging, etc.

28. Dietary Sources
Linoleic acid: walnuts, seeds, oil (soybean, corn, etc)
Linolenic acid: walnuts, oil (soybean, canola, flaxseed)
Plentiful in fatty fish and seafood
Small amounts in meat and eggs

29. Essential FA Deficiency
Rare because we have stored adipose tissues
patients receiving poor nutritional care
diseases that disrupt lipid absorption/utilization
Irritated and flaky skin
Gastrointestinal problems
Impaired immune function
Wound healing slowly
Slow growth in children

30. Pop Quiz
The body uses as the main energy source. Excess ___ (same as above) is stored as in the and muscles.
A(n) 4 , composed of 1 glycerol and fatty acids, is the long-term storage form that stores almost three times as much energy.
The body can convert fat into 6 for energy when it is necessary.