GBSN - Biochemistry (Unit 5) Chemistry of Lipids

Chemistry of Lipids

1. Biochemistry Lecture GBSN (Unit 5) Chemistry of Lipids by, Miss Areesha Ahmad Lecturer

2. Vesicles are small blisters that can appear  on your skin . Liposomes (Lips) refer to the  small spherical shape molecules formed by lipids  (e.g. phospholipids).

3. Adipose tissue , otherwise known as body fat, is  a connective tissue that extends throughout your body Fatty acid oxidation is  a series of reactions that break down fatty acids into substrates that can be used for energy production in cells Kilocalories (kcals) are  a unit of measurement for energy

4. Cell signaling is   the process by which a cell interacts with itself, other cells, and the environment .

5. Fat-soluble vitamins are absorbed along with fats in the diet and are stored in the body's fatty tissue and in the liver.  Fat-soluble vitamins (vitamins D, A, E, and K) are absorbed along with the fats you eat.

6. Common properties of lipids. Aliphatic hydrocarbons are  hydrocarbons based on chains of C atoms e.g., Alkanes Simple lipids, and do not contain fatty acids

7. Structures of Fats and Oils Fats and oils are called triglycerides because they are composed of three fatty acid units joined to glycerol: Glycerol is  a naturally occurring alcohol .

8. A wax is a simple lipid which is  an ester of a long-chain alcohol and a fatty acid . The alcohol may contain from 12-32 carbon atoms. Waxes are found in nature as coatings on leaves and stems . The wax prevents the plant from losing excessive amounts of water

9. 2.

10. Phospholipids are  amphiphilic  molecules with hydrophobic fatty acid chains and hydrophilic moieties . They occur naturally in all living organisms as the major components of cell membranes.

11. The isomers in which two similar atoms or groups of atoms lie on the same side of a double bond are stated as cis isomers

12. An ester is a chemical compound  derived from an acid (organic or inorganic) in which at least one –OH hydroxyl group is replaced  by an –O– alkyl ( alkoxy ) group

13. Sterols are  a subgroup of steroids with a hydroxyl group at the 3-position of the A-ring . The hydroxyl group on the A ring is polar. The rest of the aliphatic chain is non-polar. Covalent bond : sharing of an electron pair between two atoms Non-polar covalent bond: electron pair is shared equally between the two bonded atoms Polar covalent bond : electron pair is shared unequally between the two bonded atoms. . Polar non-polar

14. Cholesterol comprises carbon, hydrogen, and oxygen. It is a waxy, fatty substance that is solid and white or light yellow . Its chemical formula is  C 27 H 46 O . This means it has 27 atoms of carbon, 46 of hydrogen, and one of oxygen

15.   Complex lipids formed by the condensation of one, two, or three fatty acid molecules on glycerol ,  In sphingolipids the glycerol component is replaced by a long-chain amino alcohol known as sphingosine , which is amide-linked to a fatty acid and phosphate group . Fatty acids linked directly to a sugar backbone Polyketides are a rare type of lipids , normally referred as secondary metabolites, that have a biosynthetic chemistry highly similar to fatty acids Most familiar type of animal  sterol  is cholesterol,  Prenol is a building block of isoprenoid alcohols, which have the general formula:  H–[CH 2 CCH 3 =CHCH 2 ] n –OH . The repeating C 5 H 8  moiety in the brackets is called isoprene, and these compounds are sometimes called ' isoprenols

16.   estrogens, androgens, progestogens Bile salts  help with the digestion of fats

17. Hydrogenation is  a process in which vegetable oils are converted into solid vegetable ghee ( B anaspati ghee) by treating with Hydrogen in the presence of Nickel as a catalyst .

18. O xidation is when a chemical species gains oxygen In the presence of oxygen, ethers slowly autoxidize to form hydroperoxides . If concentrated or heated, these peroxides may explode Peroxide and hydroperoxides can lead to a rancid taste in oils, thus the peroxide number provides information about the freshness of the sample

19.   Hydrolysis is a chemical reaction in which water is used to break down the bonds of a particular substance

20. Phospholipids form a bilayer that acts as a semi-permeable barrier, allowing the cell to control what enters and exits . P rovides structural integrity to the cell membrane. Helps in  energy transduction, signal transduction, solute transport.

21. Soap is made by combining fats or oils with an alkali. Detergent label include:  sodium alkylbenzene sulfonate , sodium laureth sulfate

22. Soap An alkali is any base substance that dissolves in water to produce OH (hydroxide) ions and neutralise acids. Alkalis have a pH of 7 or above Alkali gropus : Lithium ( Li), Sodium ( Na), Potassium (K) Rubidium ( Rb ) Cesium (Cs) Eg, Sodium hydroxide ( NaoH ) is used  to make soap Soap is prepared by  hydrolyzing a fat under alkaline (basic) conditions . The reaction is called saponification

23. Hard water Soft water Hard water has dissolved salts and is high in minerals. Soft water has little to no minerals and lacks dissolved salts. Hard water has salts of magnesium as well as calcium as bicarbonates, sulphates , and chlorides Soft water does not have magnesium, iron, or calcium Soap scum , is a white solid that forms when soap and hard water are mixed. The scum is caused by a reaction between the soap molecules and the calcium and magnesium salts in the hard water

24. Assignment