Macro-molecules Notes (EX5) PDF

EPPERIMENT 5 Dr. RASHA AL-AZAIZEH 1 Copyright © 2010 Pearson Education, Inc.  Bio-elements: Elements in human body may be:  Essential elements: is the one whose deficiency consistently causes abnorm...

EPPERIMENT 5 Dr. RASHA AL-AZAIZEH 1 Copyright © 2010 Pearson Education, Inc.  Bio-elements: Elements in human body may be:  Essential elements: is the one whose deficiency consistently causes abnormal development or functioning and the absence of it results in death. These are divide into: A) Bulk elements: The building blocks of the compounds that constitute our organs and muscles, such as: Oxygen(O), Carbon(C), Hydrogen(H), Nitrogen(N), Sulfur(S). B) Macrominerals: They provide essential ions in body fluids and form the major structural components of the body including : Sodium (Na), Magnesium (Mg), Potassium (K), Calcium (Ca), Chlorine (Cl), and Phosphorus (P). C) Trace element: Present in very small amounts, but are not required for growth or good health. Such as: Cobalt (Co), Copper (Cu), Fluorine (F), Iodine (I), Iron (Fe), Manganese (Mn) Copyright © 2010 Pearson Education, Inc. 2  PERCENTAGE OF SOME ELEMENTS IN HUMAN BODY Copyright © 2010 Pearson Education, Inc. 3  Macromolecules The most common elements combine and form thousands of molecules. Some of these are: Small molecules: Such as water (H2O) Organic compounds: Four major categories are found in all living things, these divide into:  Macromolecules: Called polymers because they are made up from repeated subunit (monomer). This type includes: Carbohydrates, Proteins, and Nucleic acids.  Lipids: Large molecules, but not polymer. Copyright © 2010 Pearson Education, Inc. 4  Hydrolysis Hydrolysis reactions result in the breakdown of polymers into monomers by add water molecule, this reaction: I. Speed up by specific enzyme II. Break chemical bonds III. Release energy Copyright © 2010 Pearson Education, Inc. 5  Dehydration (Condensation) Dehydration reactions, a water molecule is removed as a result of generating a covalent bond between two monomeric components in a larger polymer. I. Speed up by specific enzymes II. Formation of new bonds III. Requiring energy Copyright © 2010 Pearson Education, Inc. 6  Controlled experiment  Unknown: substance we need to test  Control: to provide standard for comparison  Positive controls: it show what + result looks like (+ve)  Negative controls: it show what - result looks like (-ve)  Positive and negative controls are crucial in experimental design to ensure accuracy and reliability of results. Copyright © 2010 Pearson Education, Inc. 7  Organic compounds:  Organic compounds that contains Carbon(C), Hydrogen(H), Oxygen(O) 1. Carbohydrate:  Functions in energy storage (starch and glycogen) and structural support and protection (cellulose and chitin).  Carbohydrates represented by the formula (CH2O)n, where n is the number of carbon atoms in the molecule. In other words, the ratio of C:H:O is 1:2:1 in carbohydrate molecules. Copyright © 2010 Pearson Education, Inc. 8  CLASSIFICATION OF CARBOHYDRAYES Plant Animal Copyright © 2010 Pearson Education, Inc. 9  Monosaccharides: 1- The simplest sugar. 2- They are either: Aldoses ( ) such as Glucose and Galactose or Ketoses ( ) such as Fructose Copyright © 2010 Pearson Education, Inc. 10  Monosaccharides: 3- The number of carbon atoms usually ranges from three to six, Trioses (3 carbon atoms). Pentoses (5 carbon atoms). Hexoses(6 carbon atoms). 4- May exist as a linear chain or as ring-shaped molecules; in aqueous solutions, they are usually found in the ring form. 5- All Monosaccharides are reducing sugar. They have free aldehyde group or can tautomerize in solution to form aldehyde group if they are ketoses, as Fructose Copyright © 2010 Pearson Education, Inc. 11  Disaccharides: Made up from two monomers bind together by glycoside bond, as: Lactose Maltose Sucrose Glycosidic bond: covalent chemical bonds that hold together monomers of carbohydrate Copyright © 2010 Pearson Education, Inc. 12  Reducing sugars: Sugar classified as reducing agent if: - It can act as a reducing agent. - It has open-chain form with free aldehyde or ketone group  All monosaccharides are reducing sugars because all of them have open-chain form with free aldehyde or ketone group that tautomerize in solution to form aldehyde group. e.g. Glucose, Galactose, Fructose, Ribose, and Xylose.  Disaccharides Reducing sugars: Can convert to open-chain form with free aldehyde group, because only one of their two anomeric carbon involve in the glycoside bond. e.g. Lactose and Maltose Copyright © 2010 Pearson Education, Inc. 13  Reducing sugars: Non-reducing sugars: Can’t convert to open-chain form with free aldehyde group, because the two anomeric carbon involve in the glycoside bond. e.g. Sucrose and Trehalose  Polysaccharides are Non-reducing sugar. Copyright © 2010 Pearson Education, Inc. 14  Benedict’s test for reducing sugar:  Benedict’s reagent: is an aqueous solution of copper ion (II) (oxidizing agant), and sodium citrate with alkaline medium.  The principle:  Aldehyde group of the sugar oxidized and the copper (II) in solution reduced via the Redox reaction, then copper (I) oxide (Cu2O) precipitate is formed. The amount of precipitate which in turn depends on the amount of reducing sugar. Blue Green Yellow Orange dark red (negative) (the lowest) (the highest) Copyright © 2010 Pearson Education, Inc. 15  Experiment 1: The practical part of Benedict’s test for reducing sugar: Copyright © 2010 Pearson Education, Inc. 16  Experiment 2: Lugol’s test: Identification starch  Lugol’s solution consists Iodine in aqueous solution of potassium iodide.  Lugol’s solution interact with coiled polymer without react with other carbohydrate  The principle: Iodine react with starch to form polyiodide that result in the formation of a deep blue-black color. while Glycogen (branched form) has a slightly different structure than starch, so it gives intermediate color with Lugol’s solution Copyright © 2010 Pearson Education, Inc. 17  Lugol’s test: Copyright © 2010 Pearson Education, Inc. 18  Proteins:  They are polymer of amino acids monomers.  They act as structural components (i.e. in hair, muscles, skin, and other tissues.  Most of the enzymes in the living organisms are proteins that catalyst the speed up of biological reactions.  Diversity of protein results from differing in arrangement of 20 amino acid.  Amino acids differ only in the side chain (R). Amino acids structure Copyright © 2010 Pearson Education, Inc. 19  Proteins:  (-COOH) of the first amino acid reacts with (-NH2) of the second to form peptide bond through a dehydration reaction (remove water molecule) as the following: Copyright © 2010 Pearson Education, Inc. 20  Experiment 3: Biuret test  Biuret test to reveal the presence of peptide bonds.  The Biuret reagent is made of sodium hydroxide (NaOH) and hydrated copper(II) sulfate, together with potassium sodium tartrate. I. Sodium hydroxide: Provide alkaline condition. II. Potassium sodium tartrate: Stabilize the chelate complex.  Principles:  The reaction of the cupric ions with unshared electron pairs of the nitrogen atoms involved in peptide bonds leads to the displacement of the peptide hydrogen atoms under the alkaline conditions, this result in the formation of Chelate complex.  Chelate complex absorb the light at 540 nm and hence appears violet Copyright © 2010 Pearson Education, Inc. 21  Biuret test  The color changes from blue to pink if the concentration of peptide bonds is low like in short-chain.  The color changes from blue to Violet if the concentration of peptide bonds is high like in proteins Copyright © 2010 Pearson Education, Inc. 22  Experiment 4: Lipids  Function in energy storage and have structural purposes in living things.  They are neither huge nor polymer They are hydrophobic (Heat water) = Non polar  Lipid dissolve in non polar solvent such as: Acetone and Methanol They are three types : I. Fats ( Triglycerides): Made from Glycerol + 3 fatty acids II. Phospholipids III. Steroids Copyright © 2010 Pearson Education, Inc. 23  Fats ( Triglycerides):  The carboxyl group of each fatty acid molecules will bind to one of the hydroxyl group of glycerol through dehydration reaction to form Ester bond Copyright © 2010 Pearson Education, Inc. 24  Solubility test of fats and lipids: Copyright © 2010 Pearson Education, Inc. 25  Sudan IV Test:  Sudan IV: Reagent to detect lipids, Based on their ability to absorb pigments in the fat soluble dye (Sudan IV)  A fat-soluble dye that stains lipids red Copyright © 2010 Pearson Education, Inc. 26  Nucleic acid: Nucleic acids are large biomolecules essential for all known forms of life. They carry genetic information and are composed of long chains of nucleotide monomers. The two main types of nucleic acids are  DNA (deoxyribonucleic acid)  RNA (ribonucleic acid). Copyright © 2010 Pearson Education, Inc. 27  Nucleic acid: Copyright © 2010 Pearson Education, Inc. 28  Dische diphenylamine test: to detect the nucleic acid The Dische diphenylamine test is a chemical test used to detect the presence of deoxyribonucleic acid (DNA) specifically, by identifying the deoxyribose sugar in DNA. This test is based on a reaction between deoxyribose (a sugar found in DNA) and diphenylamine under acidic conditions, producing a blue-colored complex if DNA is present. Copyright © 2010 Pearson Education, Inc. 29  Dische diphenylamine test: Procedure: 1. Obtain 3 test tubes and number them (1-3). 2. Add 2mL DNA to tube 1 1mL H2O+1mL DNA to tube 2 2mL H2O to tube 3. 3. Add 2mL from reagent and put them in boiling water bath (10 min) and observe the results Copyright © 2010 Pearson Education, Inc. 30