1. LIPIDS

2. Lipids Made up of C, O, H Types & Functions:
Fats & Oils: energy storage & insulation
Phospholipids: building blocks of cell membranes
Steroids: structure & signaling

3. 1. Fats & Oils (triglycerides)
Most familiar
a.k.a. neutral fat
Fats – animal origin, solid at room temp.
Oils – plant origin, liquid at room temp.

4. In the body fat functions as:
Insulation against heat loss
Protective cushion for major organs
Long term energy storage (excess glucose  fat)

5. Structure: 1 glycerol + 3 fatty acids

6. Formation of a triglyceride

7. Neutral molecule (no charges)
Nonpolar
Neutral molecule (no charges)
What does this mean for how it interacts in water?

8. All are insoluble in water
(immiscible with water)
= HYDROPHOBIC
Soluble in other non-polar substances

9. FATTY ACIDS COME IN 2 Types: SATURATED & UNSATURATED

10. SATURATED Fatty Acids Saturated fats have saturated fatty acids
All C-C bonds are SINGLE
Solid at room temperature
Ex. The animal fats
Bacon fat
Butter
Lard

11. the more highly saturated the fat, the more energy it provides

13. UNSATURATED Fatty Acids
unsaturated fats have unsaturated fatty acids
some of the C-C bonds are DOUBLE
liquid at room temperature
(“kinks” formed by dbl
bonds prevent close packing)
Ex. Plant Oils
Canola oil
Safflower oil
Olive oil

14. Triglyceride - Unsaturated

15. Double bonds create kinks in the fatty acid tails  fluid consistency

16. G l y c e r o 2. Phospholipids Phosphate Fatty Acid
A phospholipid is similar to a triglyceride. It only has two fatty acids attached to a glycerol. *In addition, a phosphate molecule will also attach to the glycerol.

17. 2. Phospholipids
similar to triglycerides except that a phosphate group replaces one of the fatty acids
thus elements present are = C, H, O, P
Negatively charged polar heads are “hydrophilic” & soluble in water
Nonpolar tails are “hydrophobic” & turn away from water whenever possible

19. ~ polar head faces out / non-polar tails face in ~
PL’s make the backbone of cell membranes
~ polar head faces out / non-polar tails face in ~
Creates the lipid bi-layer we see in cells

20. Magic Milk?

21. EMULSIFICATION

22. So What?
Bile - that’s what.

23. Backbone of 4 fused carbon rings
3. Steroids
Steroids are made of several carbon rings. These carbon rings are the backbone of this type of lipid.
Backbone of 4 fused carbon rings

24. Differ by arrangement of atoms in the rings
No fatty acids
Different functional groups attached

25. Important Steroids Cholesterol Estrogen Testosterone Vitamin D
There are several important steroids in the body. *Cholesterol is a steroid. It is used along with the phospholipids the make up the cell membrane. *Vitamin D is a steroid that helps regulate the absorption of calcium from the intestines. *Estrogen in a female steroid that develops the feminine traits. It also helps to deposit calcium into bones. *Testosterone is a male steroid that develops masculine traits including the enlargement of muscles.

26. Cholesterol
Component of plasma membrane (maintains structure & fluidity)
building block for several steroids (e.g. testosterone & estrogen)