Phospholipids and Steroids

Reviews
Shared by: cara m
Stats
views:
506
rating:
not rated
reviews:
0
posted:
3/20/2008
language:
Unknown
pages:
0
Lipids Phospholipids Steroids and Cholesterol Plasma (Cell)Membranes 1 Phosphoglycerides • Most abundant lipids in cell membranes • Control cell permeability FATTY ACID glycerol FATTY ACID PO4 Amino alcohol 2 Lecithin • Abundant in brain and nerve tissues • Found in egg yolk, what germ, yeast O CH2 CH O O C O C O (C H 2 ) 1 4 C H 3 (C H 2 ) 1 4 C H 3 O - CH2 O P O + C H 2 C H 2 N (C H 3 ) 3 c h o lin e , a n a m in o a lc o h o l 3 Sphingolipids Esters of an 18-carbon alcohol sphingosine FATTY ACID sphingosine Amino alcohol 4 PO4 Sphingomyelin Found in the myelin sheath CH3(CH2)12CH=CH –CH–OH sphingosine O ‖ O fatty acid CH–NH –C –(CH2)14CH3 ‖ + CH2 –O –P –O –CH2CH2 –N–(CH3)3 ‖ O– choline 5 Steroids • Steroid nucleus • 3 cyclohexane rings • 1 cyclopentane ring steroid nucleus 6 Cholesterol • Most abundant steroid in the body • Add methyl CH3- groups, alkyl chain, and OH to steroid nucleus CH3 CH3 CH3 CH3 CH3 HO 7 Cholesterol in the Body • Cellular membranes • Myelin sheath, brain, and nerve tissue • Bile salts • Hormones • Vitamin D 8 Bile Salts • Synthesized in the liver from cholesterol • Stored in the gallbladder • Secreted into small intestine • Mix with fats to break them part • Emsulsify fat particles 9 Example of a Bile Salt c h o lic a c id , a b ile a c id CH3 OH CH3 CH3 O C N H g y c in e , a n a m in o a c id CH2 C OO N a + HO OH s o d iu m g ly c o c h o la te , a b ile s a lt 10 Steroid Hormones • Chemical messengers in cells • Sex hormones Androgens in males (testosterone) Estrogens in females (estradiol) • Adrenocorticosteroids from adrenal glands mineralocorticoids (electrolyte balance) glucocorticoids regulate glucose level 11 Sex Hormones C H 3 OH CH3 CH3 C H 3 OH O t e st o st e r o n e HO e st r a d io l 12 Plasma Membranes • Surround cells • Lipid bilayer pf phospholipids • Nonpolar hydrocarbon tails in center • Polar (hydrophilic) sections on outside • Some unsaturated fatty acids give flexibility • Keep aqueous contents inside • Allow certain biochemicals to pass through 13 Diagram of a Plasma Membrane Polar sections Nonpolar tails 14 Other Structures in Membranes • Cholesterol molecules add strength • Glycolipids on surface communicate with other cells • Proteins embedded in bilayer move certain substances (water, K+, Cl-, HCO3-) across the cell membrane • Proteins on surface act as receptors for hormones and other biochemicals 15 Learning Check PL1 Identify each lipid as: (1) phospholipid (3) triglyceride (2) steroid (4) sphingolipid A. B. C. D. E. F. G. Cholesterol Glycerol, 2 fatty acids, phosphate, and choline Glyceryl tristearate Sphingosine, fatty acid, phosphate, and choline Estradiol Bile salts Most of plasma membranes 16 Solution PL1 A. B. C. D. E. F. G. 2 steroid phospholipid 3 triglyceride 4 sphingolipid 2 steroid 2 steroid 1 phospholipid 17

Related docs
Other docs by cara m
diagrams
Views: 397  |  Downloads: 19
verb
Views: 481  |  Downloads: 49
Subject-Verb Agreement
Views: 633  |  Downloads: 45
Spelling
Views: 365  |  Downloads: 39
Avoiding Run-On Sentences
Views: 532  |  Downloads: 24
Types of Reactions
Views: 431  |  Downloads: 24
Subshells and Orbitals
Views: 523  |  Downloads: 29
Strengths of Acids and Bases - Making Dilutions
Views: 480  |  Downloads: 15
ph
Views: 609  |  Downloads: 16
Orbital Diagrams
Views: 1100  |  Downloads: 9
Nucleic Acids
Views: 198  |  Downloads: 12
Nuclear Radiation
Views: 329  |  Downloads: 23
moles and molar mass
Views: 438  |  Downloads: 8
Metabolic Pathways and Energy Production
Views: 170  |  Downloads: 6