Carbohydrates and Lipids PDF

BIOCHEMISTRY: CHEMISTRY OF LIFE (Carbohydrates, Lipids, Proteins, Nucleic Acids, Vitamins and Minerals) PREPARED BY: EARL JUSTINE S. PALLERA SENIOR HIGH SCHOOL DEPARTMENT GEN. VITO BELARMINO INTEGRATED NATIONAL HIGH SCHOOL Biochemistry is the study of chemical comp...

BIOCHEMISTRY: CHEMISTRY OF LIFE (Carbohydrates, Lipids, Proteins, Nucleic Acids, Vitamins and Minerals) PREPARED BY: EARL JUSTINE S. PALLERA SENIOR HIGH SCHOOL DEPARTMENT GEN. VITO BELARMINO INTEGRATED NATIONAL HIGH SCHOOL Biochemistry is the study of chemical composition and reactions of living matter. Organic Inorganic compounds compounds ✓ Carbohydrates, fats, ✓Water, salts, and many proteins, and nucleic acids acids and bases ✓ Contain carbon, are usually ✓Do not contain carbon large, and are covalently bonded  The Molecules of Life  Within cells, small organic molecules are joined together to form larger molecules  Macromolecules are large molecules composed of thousands of covalently connected atoms Most macromolecules are polymers, built from monomers A polymer is a long molecule consisting of many similar building blocks called monomers Three of the four classes of life’s organic molecules are polymers:  Carbohydrates  Proteins  Nucleic acids  Lipids  The Synthesis and Breakdown of Polymers  Monomers form larger molecules by condensation reactions called dehydration reactions  Polymers are disassembled to monomers by hydrolysis, a reaction that is essentially the reverse of the dehydration reaction  Short polymer Unlinked monomer Dehydration removes a water molecule, forming a new bond Longer polymer Dehydration reaction in the synthesis of a polymer Hydrolysis adds a water molecule, breaking a bond Hydrolysis of a polymer  The Diversity of Polymers  Each cell has thousands of different kinds of macromolecules  Macromolecules vary among cells of an organism, vary more within a species, and vary even more between species  Animmense variety of polymers can be built from a small set of monomers SIX CLASSIFICATION OF NUTRIENTS 1. Water 2. Carbohydrates (sugars, starch, cellulose) 3. Lipids (fats) 4. Proteins and Nucleic Acid 5. Vitamins 6. Minerals  Carbohydrates serve as fuel and building material  Carbohydrates include sugars and the polymers of sugars  The simplest carbohydrates are monosaccharides, or single sugars  Carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocks Sugars  Monosaccharides have molecular formulas that are usually multiples of CH2O  Glucose is the most common monosaccharide  Monosaccharides are classified by location of the carbonyl group and by number of carbons in the carbon skeleton  Triose sugars Pentose sugars Hexose sugars (C3H6O3) (C5H10O5) (C6H12O6) Ribose Glyceraldehyde Glucose Galactose Dihydroxyacetone Ribulose Fructose  Monosaccharides serve as a major fuel for cells and as raw material for building molecules  Though often drawn as a linear skeleton, in aqueous solutions they form rings Linear and Abbreviated ring ring forms structure MONOSACCHARIDES  GLUCOSE  It is the most comoon hexose in the body.  It is an instatnt source of fuel in body cells.  FRUCTOSE It is commonly found in ripened fruits and honey. It is the sweetest sugar.  GALACTOSE It is produced in the mammary glands of lactating animals. It binds with glucose to form sugar in milk. DISACCHARIDES A DISACCHARIDE IS FORMED WHEN A DEHYDRATION REACTION JOINS TWO MONOSACCHARIDES THIS COVALENT BOND IS CALLED A GLYCOSIDIC BOND LACTOSE = GLU + GAL MALTOSE = GLU + GLU SUCROSE = GLU + FRU  MALTOSE It is also caIled as malt sugar. It is formed by the reaction of two glucose units.  SUCROSE  It is the common table sugar.  It is formed by the reaction of with one molecule of glucose with one molecule of fructose.  LACTOSE  It is the least sweet sugar.   It is formed when one molecule of glucose reacts with one molecule of galactose. POLYSACCHARIDES Glycogen granules in muscle tissue Glycogen Cellulose Cellulose Hydrogen bonds molecules between —OH groups (not shown) attached to carbons 3 and 6 POLYSACCHARIDES These are the complex carbohyrates made up of many sugar molecules linked together in a chain.  Polysaccharides,the polymers of sugars, have storage and structural roles  The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages Storage Polysaccharides  Starch,a storage polysaccharide of plants, consists entirely of glucose monomers  Plants store surplus starch as granules within chloroplasts and other plastids  Glycogen is a storage polysaccharide in animals  Humans and other vertebrates store glycogen mainly in liver and muscle cells  STARCH It is a common component of plant.  GLYCOGEN It is the animal starch formed by glucose molecules. It is not present in the food we eat. a Glucose b Glucose a and b glucose ring structures Starch: 1–4 linkage of a glucose monomers. Cellulose: 1–4 linkage of b glucose monomers. Structural Polysaccharides  Cellulose is a major component of the tough wall of plant cells  Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ  The difference is based on two ring forms for glucose: alpha () and beta ()  CELLULOSE It is a form of carbohydrate similar to starch. It is also composed of several units of glucose.  CHITIN It is a polysaccharide similar to cellulose. It forms an important structural component fo the exoskeleton of artropods.  Lipids are a diverse group of hydrophobic molecules  Lipids are the one class of large biological molecules that do not form polymers  The unifying feature of lipids is having little or no affinity for water  Lipids are hydrophobic because they consist mostly of hydrocarbons, which form nonpolar covalent bonds  The most biologically important lipids are fats, phospholipids and steroids FATS  Fats are constructed from two types of smaller molecules: glycerol and fatty acids  Glycerolis a three-carbon alcohol with a hydroxyl group attached to each carbon A fatty acid consists of a carboxyl group attached to a long carbon skeleton  Fatty acid (palmitic acid) Glycerol Dehydration reaction in the synthesis of a fat  Fats separate from water because water molecules form hydrogen bonds with each other and exclude the fats In a fat, three fatty acids are joined to glycerol by an ester linkage, creating a triacylglycerol, or triglyceride  Ester linkage Fat molecule (triacylglycerol)  Fatsmade from saturated fatty acids are called saturated fats  Most animal fats are saturated  Saturated fats are solid at room temperature A diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits  Stearic acid Saturated fat and fatty acid.  Fatsmade from unsaturated fatty acids are called unsaturated fats  Plant fats and fish fats are usually unsaturated  Plant fats and fish fats are liquid at room temperature and are called oils  Oleic acid cis double bond causes bending Unsaturated fat and fatty acid. PHOSPHOLIPIDS  In a phospholipid, two fatty acids and a phosphate group are attached to glycerol  Thetwo fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head  When phospholipids are added to water, they self- assemble into a bilayer, with the hydrophobic tails pointing toward the interior  Thestructure of phospholipids results in a bilayer arrangement found in cell membranes  Phospholipids are the major component of all cell membranes Steroids  Steroidsare lipids characterized by a carbon skeleton consisting of four fused rings  Cholesterol, an important steroid, is a component in animal cell membranes  Although cholesterol is essential in animals, high levels in the blood may contribute to cardiovascular disease