1. Compound and Derived Lipids

2. Glycerophospholipids
Glycerophospholipids are:
The most abundant lipids in cell membranes.
Composed of glycerol, two fatty acids, phosphate and an amino alcohol.
Fatty acid
Glycerol
Fatty acid
PO4
Amino
alcohol

3. Phospholipids Hydrophilic Hydrophobic Polar Head Glycerol
Fatty Acid Tails
Hydrophilic
Hydrophobic

4. Polarity of Glycerophospholipids
A glycerophospholipid has polar and nonpolar regions.

5. Lecithin and Cephalin Lecithin and cephalin are glycerophospholipids:
Abundant in brain and nerve tissues.
Found in egg yolk, wheat germ, and yeast.

7. Sphingolipids
Sphingolipids are phospholipids that have an amide bond between a fatty acid and sphingosine, an 18-carbon alcohol.

8. Glycosphingolipids
Glycosphingolipids (cerebrosides and gangliosides) contain monosaccharides bonded to the –OH of sphingosine by a glycosidic bond.
Cerebrosides contain only one monosaccharide.

9. Gangliosides
Gangliosides are similar to cerebrosides, but contain two or more monosaccharides.

10. Lipid Diseases (Lipidoses)
In many lipid diseases, the deficiency of an enzyme causes the accumulation of glycolipids.

12. Steroids steroid nucleus Steroids are:
Lipids containing the steroid nucleus, which is a fused structure of four rings.
Found in cholesterol, bile salts, hormones, and vitamin D.
steroid nucleus

13. Steroids Complex ring forms Some hormones Cholesterol
Natural substance
Found in membranes
Gives membranes natural flexibility

14. Steroids
Cholesterol
Estradiol
Testosterone

15. Cholesterol The most abundant steroid in the body.
Contains 27 carbon atoms.
At C3 there is a –OH group; so it is an alcohol.
Composed of the steroid nucleus with methyl groups, an alkyl chain, and a hydroxyl group attached.
Precursor for adrenal corticosteroids, vitamin D and bile acids

16. Cholesterol in Foods Cholesterol:
Is considered elevated if plasma cholesterol exceeds mg/dL.
Is synthesized in the liver and obtained from foods.
100 g 1
1 tablespoon
1 cup
1 tablespoon

17. Lipoproteins Combine lipids with proteins and phospholipids.
Are soluble in water because the surface consists of polar lipids.

18. Types of Lipoproteins Lipoproteins:
Differ in density, composition, and function.
Include low-density lipoprotein (LDLs) and high-density lipoprotein (HDLs).

19. Transport of Lipoproteins in the Body

20. Bile Salts
Are synthesized from cholesterol and stored in the gall bladder.
Emulsify fats and oils to give a greater surface area for lipid digesting enzymes.

21. Steroid Hormones Steroid hormones: Are produced from cholesterol.
Include sex hormones such as androgens (testosterone) in males and estrogens (estradiol) in females

22. Estradiol
Testosterone

23. Adrenal Corticosteroids
Steroid hormones called adrenal corticosteroids:
Are produced by the adrenal glands located on the top of each kidney.
Include aldosterone, which regulates electrolytes and water balance by the kidneys.
Include cortisone, a glucocorticoid, which increases blood glucose level and stimulates the synthesis of glycogen in the liver.

24. Adrenal Corticosteroids

25. Lipid Profile Lipid profile includes: 1)Total lipids 2)Triglycerides
3) Cholesterol
4) HDL
5) LDL
These tests must be carried out after hrs. fasting due the high molecular weight of lipid molecules and the prolonged digestion and metabolism.

26. Phospholipids
Polar group

27. Phospholipid Bilayer

28. Micelles

29. A Composite Cell Major parts include: Nucleus Cytoplasm Cell membrane
Phospholipid bilayer
Flagellum
Nucleus
Nuclear envelope
Chromatin
Nucleolus
Ribosomes
Microtubules
Basal body
Cell membrane
Centrioles
Rough
Endoplasmic
reticulum
Mitochondrion
Smooth
Endoplasmic
reticulum
Major parts include:
Nucleus
Cytoplasm
Cell membrane
Microvilli
Secretory
vesicles
Cilia
Golgi
apparatus
Microtubule
Microtubules
ysosomes L

30. Cell Membranes Cell membranes:
Separate cellular contents from the external environment.
Consist of a lipid bilayer made of two rows of phospholipids.
Have an inner portion made of the nonpolar tails of phospholipids with the polar heads at the outer and inner surfaces.

31. Cell Membrane Fibrous protein Carbohydrate Glycolipid Glycoprotein
Extracellular side
of membrane
Cytoplasmic side
Cholesterol
molecules
Globular
protein
Double
layer of
Phospholipid
Hydrophobic
fatty acid
“tail”
Hydrophilic
Phosphate
“head”
Cell membrane
“Heads” of
phospholipid
“Tails” of

32. Fluid Mosaic Model of Cell Membranes
The lipid bilayer contains proteins, carbohydrates, and cholesterol.
The unsaturated fatty acids make cell membranes fluid- like rather than rigid.
Proteins and carbohydrates on the outer surface communicate with hormones and neurotransmitters.

33. Transport Through Cell Membranes
Diffusion (passive transport) moves particles from a higher to a lower concentration.
Facilitated transport uses protein channels to increase the rate of diffusion.
Active transport moves ions against a concentration gradient.