1 / 20

Lipids

Lipids. Lipids. Made up of C, H and O Can exist as fats, oils and waxes They are insoluble in water They are a good source of energy (9 k cal / g ) They are poor conductors of heat Most fats & oils are triglycerides. Lipids. Biomolecules that contain fatty acids or a steroid nucleus.

cuyler
Download Presentation

Lipids

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Lipids

  2. Lipids • Made up of C, H and O • Can exist as fats, oils and waxes • They are insoluble in water • They are a good source of energy • (9 k cal / g) • They are poor conductors of heat • Most fats & oils are triglycerides

  3. Lipids • Biomoleculesthat contain fatty acids or a steroid nucleus. • Soluble in organic solvents, but not in water. • Named for the Greek word lipos, which means “fat.” • Extracted from cells using organic solvents.

  4. C O H H C O H H C O H H Triglycerides • Formed by esterification (condensation reaction between 3 fatty acids and glycerol) H Glycerol H

  5. H H H H H H H C C C C C C C O C H H H H H H H O H Fatty acids • Carboxyl group (-COOH) • attached to a long non-polar hydrocarbon chain (hydrophobic) H A saturated fatty acid (no double bonds)

  6. H H H H H H H H C C C C C C C C H H H H H H H H H O C H C C O H H A monounsaturated fatty acid H H O C C H C C C O H H H A polyunsaturated fatty acid

  7. H H H H C C C C O C O H H C H H H H O C O H H H C O H H Esterification H Fatty acid Glycerol H

  8. H H H H C C C C O C O H H C H H H H O C O H H H C O H H Esterification H Fatty acid Glycerol H

  9. H H H H C C C C O C O H H C H H H H C O H H C O H Esterification H O H H Fatty acid Glycerol H

  10. H H H H C C C C O C O H H C H H H H C O H H C O H Esterification H Ester bond O H H H water

  11. Esterification • This happens three times to form a triglyceride glycerol fatty acids

  12. Phospholipids One fatty acid can be replaced by a polar phosphate group hydrophilic phosphate glycerol Hydrophobic fatty acids

  13. Classification of Lipids • Simple lipids • Compound lipids (Complex) • Derived lipids

  14. Simple lipids • The alcohol is glycerol • Oil (liquid at room temperature) • Fat (solid at room temperature) • Natural lipids need 3 F.As. and one molecule of glycerol to form triglycerides + 3 H2O A) Natural Lipids

  15. Simple lipids • Most natural waxes are esters derived from a fatty acid and a long-chain alcohol • Main biological function of waxes: water barrier • Bee waxes are formed by honey bee and formed from merioyl alcohol and palmitic acid. B) Waxes

  16. Cerotic acid A fatty acid remove H2O Myricyl alcohol Long chain alcohol Myricylcerotate Present in beeswax Feathers Wax minimizes wetting Leaves Wax minimizes water evaporation Waxes • Most natural waxes are esters derived from a fatty acid and a long-chain alcohol • Main biological function of waxes: water barrier

  17. Compound lipids • F.A + alcohol + other group • Phospholipids (contain phosphate group) • Glycolipids (contain carbohydrates) • Lipoproteins (contain proteins)

  18. Derived lipids • Hormones • Steroids

  19. Diversity in structure leads to a diversity in biological function • Non-polar lipids (fats) are the principal molecules for energy storage. • Polar lipids (nitrogen and phosphorus containing) are components of biological membranes. • The steroid (class of lipids) (cholesterol) is found in biological membranes and used as a precursor for many hormones, bile and vitamin D • Miscellaneous lipids present only in minor quantities in the cell are involved as light-absorbing pigments (β-carotene, retinal), enzyme cofactors (vitamin K), signal molecules (prostaglandins), and electron carries.

  20. Diversity in structure leads to a diversity in biological function • Used as a fuel reserve (when needed) • Provide body with essential fatty acids • Fats under skin (subcutaneous) are used as insulator and protecting and maintaining the body temperature. • Fats provide the protection and fixation of internal organs. • Lipoproteins enter in the formation of cell wall, muscles, mitochondria and microsomes.

More Related