TOPIC 3.2 Carbohydrates, Lipids and Proteins

3.2.1 Organic and Inorganic Organic Compounds Inorganic Compounds Produced by living things All C containing compounds found in living things except hydrogencarbonates (HCO3-), carbonates (CO32-) and oxides of carbon (CO and CO2) Inorganic Compounds All other compounds

Important Organic Compounds in Living Things (biochemicals) Molecule Subcomponents (precursors or subunits) Example Molecules carbohydrates monosaccharides monosaccharides: glucose, galactose, fructose disaccharides: maltose, lactose, sucrose polysaccharide: starch, glycogen, cellulose proteins amino acids enzymes, antibodies lipids fatty acids triglyceride, phospholipid nucleic acids nucleotides DNA, RNA

3.2.2 Identify Glucose & Ribose from Diagrams Carbohydrates contain C, H and O in approximately a 1:2:1 ratio Building blocks = monosaccharides or simple sugars Types of carbohydrates: Monosaccharides (one simple sugar molecule) Disaccharides (two simple sugar molecules covalently bonded together) Polysaccharides (many simple sugar molecules covalently bonded together

Glucose – a monosaccharide C6H12O6 Hexagon shape with 6 carbon atoms

Ribose – a monosaccharide (pentose sugar = 5 carbon atoms) C5H10O4 Deoxyribose is the sugar component of DNA C5H10O5 Ribose is the sugar component of RNA

3.2.3 Monosaccharide, Disaccharide and Polysaccharide (3 examples of each) Monosaccharides = glucose, fructose and galactose (all C6H12O6) Isomers = same chemical formula, but different structural formula Disaccharides = maltose, sucrose and lactose Isomers (all C12H22O11) Polysaccharides = starch, glycogen and cellulose Plants store glucose as the polysaccharide starch Animals store glucose as the polysaccharide glycogen

3.2.4 Functions of Carbohydrates in Animals and Plants Glucose = source of E ; glucose is broken down to produce ATP in cellular respiration Lactose = sugar found in milk of mammals; source of E Glycogen = used for short term E storage in the liver and muscles Plants: Fructose = very sweet; good source of E (found in fruits) Sucrose = used to transport and store E Cellulose = one of the primary components of cell walls

3.2.5 Condensation Reaction (dehydration synthesis) Two molecules of glucose form maltose plus water condensation reaction= a water molecule is removed as two glucose combine to form maltose (also called dehydration synthesis) C6H12O6 + C6H12O6 C12H22O11 + H2O

Condensation and Hydrolysis Reactions (cont.) glucose + glucose maltose + water glucose + fructose sucrose + water glucose + galactose lactose + water this direction ( ) indicates condensation this direction ( ) indicates hydrolysis (hydro = water; lysis = splitting)

3.2.2 Identify Fatty Acids from Diagrams the building blocks of lipids lipids include triglycerides (glycerol plus three fatty acids), phospholipids and steroids (ex. cholesterol) triglyceride structure: condensation reaction unsaturated fatty acid saturated fatty acids

3.2.6 Lipids contain C, H and O atoms, but not in a 1:2:1 ratio like carbohydrates…lipids contain very few O atoms fats and oils are lipids fats generally come from animals; they are solid at room T°; contain single bonds and are saturated oils generally come from plants; they are liquid at room T°; contain 1 or more double bonded carbon atoms and are unsaturated lipids store twice the energy of carbohydrates important for insulation, Energy storage and membrane structure

3.2.2 Identify Amino Acids from Diagrams polypeptides are long chains of amino acids amino acids are the building blocks of proteins 20 different amino acids all have similar structure: central C atom has four groups attached to it: amine group - NH2 carboxyl group - COOH a hydrogen atom - H the “R” group which is different in different amino acids

Generalized Amino Acid Structure

Amino Acids Form Chains Condensation Reactions polypeptide chains are formed through condensation reactions (dehydration synthesis) at ribosomes water molecule removed