脂肪英文课件

phosphorus containing compound Found in body Synthesized by the body as needed
Functions of Phospholipids
Makes up cell membrane Eicosanoid synthesis Emulsifier
H--C--O--C-- Fatty Acid O
H--C--O--C-- Fatty Acid
H
esterification/reesterification
desterfication
Phospholipids
Built on a glycerol backbone Has at least one fatty acid replaced with
docosahexaenoic acid (DHA) are related Metabolized to form eicosanoids Recommend intake of ~2 servings of fish
per week
Essential Fatty Acid- Omega-6 (linoleic acid)
Chap. 6: Lipids
Fats- solid at RT Oils- Liquid at RT
Fatty Acids Saturated vs unsaturated
Triglycerides Phospholipids Cholesterol
Figure 6-1
Goals for the chapter
< 6 Carbons
Essential Fatty Acids
Must be eaten Body can only make double bonds
after the 9th carbon from the omega end Needed for immune function, vision, cell membrane, and production of hormone-like compounds
Bile acids Lecithins
Emulsifier
Hydrophilic end (attracts water)
Hydrophobic end (attracts lipid)
Emulsification
Sterols
A multi-ringed structure Do not have a glycerol backbone Waxy substance Do not readily dissolve in water Cholesterol is a sterol
O H--C--O--C-- R + H20
H
(Ester bond) Triglyceride +
3 H20
Triglycerides
H H--C--OH
H--C--OH
H--C--OH H
HO
Fatty Acid
+ Fatty Acid
Fatty Acid
H--C--O--C-- Fatty Acid O
Sources of Dietary Lipids
Triglycerides
H H--C--OH
H--C--OH
H--C--OH H
O HO-C-R
O
+ HO-C-R
O HO-C-R
Glycerol + 3 FA’s
HO H--C--O--C-- R + H2O
O H--C--O--C-- R + H20
Fatty Acid Structure
H H H H H H H H H H H H H H H HHO H-C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C-C-OH
HHHH HHHHH HHHHHHH H
omega end
alpha end degree of saturation
Essential Fatty Acid- Omega-3 (alpha-linolenic acid)
H H H H H H H H H H H H H H H HH O
H-C--C--C=C--C--C =C--C--C=C--C--C--C--C--C--C--C--C-OH
HH
H
H
HHHH HHH
Omega-6 eicosanoids; Archidonic acid
increase blood clotting increase inflammatory responses
Omega-3 eicosanoids, DHA, EPA
decrease blood clotting reduce heart attack excess may cause hemorrhagic stroke
Precursor to bile acids
Content Review
What are some important functions of the essential fatty acids?
How are saturated fatty acids different from unsaturated fatty acids?
omega end
alpha end
1st double bond is located on the 3rd carbon from the omega end
Omega-3 Fatty Acid
Primarily from fish oil Also found in canola or soybean oil Eicosapentaenoic acid (EPA) and
4H
Eicosapentaenoic Acid (C20:5)
(EPA)
2C
2H
Arachidonic acid (C20:4)
4H
Docosahexaenoic Acid (C22:6) (DHA)
Eicosanoids
A group of hormone-like compounds Regulates blood pressure, childbirth,
Functions of Cholesterol
Essential component of cell membrane Produced by the liver Found only in animal products Forms important hormones
Estrogen, testosterone, vitamin D
clotting, immune responses, inflammatory responses, & stomach secretions By-pass the blood stream and work in the area of origin
Eicosanoids Have Different Effects
HHHH HHHHH HHHHHHHH
omega end One double bond
alpha end
Polyunsaturated Fatty Acid Structure
HHHH H
H
H H H H H HH O
H-C--C--C--C--C--C=C--C--C=C--C--C--C--C--C--C--C--C-OH
alpha end
degree of saturation: single carbon bond
Monounsaturated Fatty Acid Structure
HHHH HHHH
HH HHHHHO
H-C--C--C--C--C--C--C--C--C=C--C--C--C--C--C--C--C--C-OH
Omega-6 Fatty Acid
Found in vegetable oils Only need ~ 1 tablespoon a day Arachidonic acid can be made from omega-6 Metabolized to form eicosanoids
Omega-6 Fatty Acid
Omega-6
Omega-3 Fatty Acids
Omega-3 (C18:3)
Linoleic Acid (C18:2)
2C 2H
Dihomo-gama-linolenic acid (C20:3)
Alpha-linolenic Acid (C18:3)
2C
Describe the different types of lipids Describe the essential fatty acids and explain how they relate to health and cardiovascular disease Discuss fat digestion and absorption Name the classes of lipoproteins and classify them according to function Describe fat replacements
HHHH HHHHH HHHHHHHH
omega end > 2 double bonds
alpha end
Chain Length of Fatty Acids
Long chain FA
> 12 Carbons
Medium chain FA
6 - 10 Carbons
Short chain FA
food and body (storage) Energy dense (9 kcal /gm)
Functions of Lipids
Provide energy Efficient storage of energy Insulation Protection Transport fat-soluble vitamins Satiety Flavor and mouth feel
Saturated Fatty Acid Structure
H H H H H H H H H H H H H H H HHO H-C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C-C-OH
HHHH HHHHH HHHHHHH H
omega end
Characterize symptoms of cardiovascular disease and discuss risk factors
Properties of Lipids
Do not readily dissolve in water Fats are solid at room temperature Oils are liquid at room temperature Triglycerides are the main form of lipids in
HHHH H
H
HH H HHHHO
H-C--C--C--C-- C--C =C--C--C=C--C--C--C--C--C--C--C--C-OH
HHHH HH HHH HHHHHHH H
omega end
alpha end
1st double bond is located on the 6th carbon from the omega end
What is esterification? What are the main functions of lipid in the body? What are emulsifiers?
Eicosanoid has different t on different tissues
Signs and Symptoms of Essential Fatty Acids Deficiency
Flaky, itchy skin Diarrhea Infections Retarded growth and wound healing Anemia