1. Lipids

2. LIPIDS Elements: CHOP - mostly HYDROPHOBIC - MOSTLY hydrocarbons
NET affect - NON-POLAR
Types: fats and oils
phospholipids steroids waxes

3. Function: 1. energy storage – fat and oil 2
Function: 1. energy storage – fat and oil 2. Protection and insulation - fat Ex: Blubber 3. structure – phospholipids and cholesterol 4. chemical communication - steroids 5. repel water- waxes

5. FATS AND OILS Structure - two parts
1. glycerol - three carbon chain with three hydroxyls
2. fatty acid - long chain of hydrocarbons with a carboxyl head
carboxyl head combines with hydroxyl of glycerol by dehydration synthesis so 3 fatty acids combine with the glycerols = triglycerol or triglyceride
The massive amounts of hydrocarbons in the tail make fats NONPOLAR

6. Fats and Oils
Constructed from a glycerol and three fatty acids Result = TRIGLYCERIDE

7. FATS vs. OILS FATS - animal derived - solid at room temp
OILS - mostly plant derived - liquid at room temp
crucial difference?
bonding in the fatty acids tails

8. - Fats are saturated - Oils are unsaturated both have the same basic structure of glycerol plus three fatty acids - fats: fatty acids are all single bonds making the chains essentially straight - pack together nicely - solid at room temperature - oils: fatty acids are unsaturated due to double bonds - causes the chains to bend in the cis conformation - don’t pack together very nicely – liquid at room temperature

12. (a) Saturated fat and fatty acid
Saturated fatty acids
Have the maximum number of hydrogen atoms possible
Have no double bonds
(a) Saturated fat and fatty acid
Stearic acid
Figure 5.12

13. (b) Unsaturated fat and fatty acid
Unsaturated fatty acids
Have one or more double bonds
(b) Unsaturated fat and fatty acid
cis double bond
causes bending
Oleic acid
Figure 5.12

14. PARTIALLY HYDROGENATED OILS
BAD BAD BAD BAD BAD

15. Hydrogenated Oils
Unsaturated oils are heated and treated with hydrogen gas and a catalyst to break the double bond and add hydrogen
- this makes them saturated
Heating the oils can also cause isomerization and switch the cis double bond to a trans double bond making it a TRANS fat
TRANS fats are not able to be processed by our cells and lead a higher interaction with “bad” cholesterol and can potentially lead to inflammation in the blood vessels exacerbating heart disease

16. k

17. ENERGY Content of Foods
- fats and oils: 9 Cal/g
- carbs: 4 Cal/g
- protein: 4 Cal/g
- alcohol: 7 Cal/g

18. PHOSPHOLIPIDS
Function: STRUCTURE - cell membranes Composition: Hydrophilic head: - phosphate joined to glycerol = POLAR - joins with other polar molecules Hydrophobic tail: two chains not three

19. (a) Structural formula (b) Space-filling model
Phospholipid is amphipathic
Both hydrophilic and hydrophobic
CH2 O P CH C
Phosphate
Glycerol
(a) Structural formula
(b) Space-filling model
Fatty acids
(c) Phospholipid
symbol
Hydrophobic tails
Hydrophilic
head
Hydrophobic
tails –
Hydrophilic head
Choline +
Figure 5.13
N(CH3)3

20. Reaction with water: heads out tails in 1. micelle 2
Reaction with water: heads out tails in 1. micelle 2. liposome - cell membrane – PHOSPHOLIPID BILAYER

21. Phospholipids in Water

22. The structure of phospholipids
Results in a bilayer arrangement found in cell membranes
Hydrophilic
head
WATER
Hydrophobic
tail
Figure 5.14

23. Steroids four fused rings examples: testosterone estrogen
cholesterol - stabilize cell membranes

24. Estradiol Testosterone
CH3 OH HO O
Estradiol
Testosterone
Female lion
Male lion
Figure 4.9

25. Cholesterol Is found in cell membranes
Is a precursor for some hormones HO
CH3
H3C

26. Understanding Blood Lipid Panel
Total Cholesterol:
Composite of triglyceride levels, LDL, and HDL
Triglycerides:
Normal Levels: 150 mg/dL
Function: energy – body converts extra energy to triglycerides (fat) and stores it

27. LDL: Low Density Lipoproteins - “bad” cholesterol
Function: transport cholesterol throughout the body for absorption by the cells
Normal Levels: Between 100 – 129 mg/dL
Issues: LDL bind more readily to the glycoproteins on the surface of the blood vessel endothelium (cell on the surface of the wall) and become oxidized  forms fatty plaques (atherosclerosis) that can harden (arteriosclerosis) to narrow the diameter of the blood vessels and make them less flexible (increases blood pressure)

28. HDL: High Density Lipoproteins
“good” cholesterol
Normal Levels: mg/dL for men
50 – 60 mg/dL for women
> 60 mg/dL = lower risk of heart disease
Function: removal of lipids from the blood stream

31. Hypercholesterolemia
Genetic condition that causes a lack of LDL receptors on the surface of cells
Result in very high levels of cholesterol in blood

32. Animation of LDL receptors Receptor Mediated Endocytosis
Part II

33. The deal with Fats
Unconventional But Effective Therapy for Alzheimer's Treatment: Dr. Mary T. Newport at TEDxUSF