Jadara University Faculty of Pharmacy General Biology Lecture Notes PDF

Jadara University Faculty of Pharmacy Medical Laboratory Sciences Department General biology 1 (187104) Lecture # 1 Introduction New Properties Emerge at Successive Levels of Biological Organization Textbook Campbell biology, Lisa Urry, Michael Cain,...

Jadara University Faculty of Pharmacy Medical Laboratory Sciences Department General biology 1 (187104) Lecture # 1 Introduction New Properties Emerge at Successive Levels of Biological Organization Textbook Campbell biology, Lisa Urry, Michael Cain, Steven Wasserman, Peter Minorsky, Jane Reece, 2021, 12th ed.  Chapter 5 General Biology The Structure and Function of Large Biological (BIO101) Molecules Lecture Presentations by Nicole Tunbridge and © 2017 Pearson Education, Inc. Kathleen Fitzpatrick  a) Biology is the scientific study of life b) “Life is recognized by what living things do” © 2015 Pearson Education Ltd  Theme: New Properties Emerge at Successive Levels of Biological Organization a) Life can be studied at different levels, from molecules to the entire living planet b) This enormous range can be divided into different levels of biological organization © 2015 Pearson Education Ltd Figure 1.3 The Biosphere 1 7 Tissues 6 Organs 2 and Organ Ecosystems Systems 10 3 Mole- Communities cules 8 Cells 5 Organisms 9 Organelles 4 Populations © 2015 Pearson Education Ltd  Chapter 1 The Structure and Function of Large Biological Molecules © 2015 Pearson Education Ltd  Biological Macromolecules The Large Biological Molecules are The Organic Molecules of Life serving as: (a) Energy sources (b) Building materials What are these macromolecules? © 2015 Pearson Education Ltd  The molecules of Life All living things are made up of four classes of large biological molecules: (1) Carbohydrates, (2) Proteins, (3) Nucleic acids, and (4) Lipids © 2015 Pearson Education Ltd  The Large Biological Molecules are polymers, built from monomers © 2015 Pearson Education Ltd The Large Biological Molecules are polymers, built from monomers a) A polymer (= many parts) is a long molecule consisting of many similar building blocks b) The repeating units that serve as building blocks are monomers (= single parts) © 2015 Pearson Education Ltd The Large Biological Molecules are polymers, built from monomers Three of the four classes of life’s organic molecules are polymers: a) Carbohydrates b) Proteins c) Nucleic acids © 2015 Pearson Education Ltd  Synthesis & Breakdown of Polymers © 2015 Pearson Education Ltd The Synthesis and Breakdown of Polymers a) Synthesis of polymers occurs through dehydration (condensation) reaction: bonding of or linking monomers through the loss of water molecules b) Polymers are disassembled (broken down) to monomers by hydrolysis, the reverse of the dehydration reaction c) Enzymes are specialized macromolecules that speed up chemical reactions such as those that make or break down polymers © 2015 Pearson Education Ltd Figure 5.2 (a) Dehydration reaction: synthesizing a polymer 1 2 3 Short polymer Unlinked monomer Dehydration removes a water H2O molecule, forming a new bond. 1 2 3 4 Longer polymer (b) Hydrolysis: breaking down a polymer 1 2 3 4 H2O Hydrolysis adds a water molecule, breaking a bond. 1 2 3 © 2015 Pearson Education Ltd  Question How many water molecules are needed to completely hydrolyze a polymer that is 101 monomers long? © 2015 Pearson Education Ltd  The molecules of Life Four classes of large biological molecules: (1) Carbohydrates, (2) Proteins, (3) Nucleic acids, and (4) Lipids © 2015 Pearson Education Ltd  Carbohydrates a) Most abundant organic molecules in nature b) Comprised of three main atoms: C, H, O c) Serve as fuel (energy source) and building materials (carbon skeleton) c) Include both sugars (simplest carbohydrates) and polymers of sugars (larger carbohydrates). © 2015 Pearson Education Ltd  Sugars a) Monosaccharides b) Disaccharides c) Polysaccharides © 2015 Pearson Education Ltd 18  Sugars a) Monosaccharides b) Disaccharides c) Polysaccharides © 2015 Pearson Education Ltd 19  Sugars: Monosaccharides Monosaccharides are the simplest sugars Have molecular formulas that are usually multiples of (CH2O)n Glucose (C6H12O6) is the most common Classified by: a) The location of the carbonyl group (as aldose or ketose) b) The number of carbons in the carbon skeleton © 2015 Pearson Education Ltd Figure 5.3 Aldoses (Aldehyde Sugars) Ketoses (Ketone Sugars) Trioses: 3-carbon sugars (C3H6O3) Glyceraldehyde Dihydroxyacetone Pentoses: 5-carbon sugars (C5H10O5) Ribose Ribulose Hexoses: 6-carbon sugars (C6H12O6) Glucose Galactose Fructose © 2015 Pearson Education Ltd Figure 5.3a Aldose (Aldehyde Sugar) Ketose (Ketone Sugar) Trioses: 3-carbon sugars (C3H6O3) Glyceraldehyde Dihydroxyacetone © 2015 Pearson Education Ltd Figure 5.3b Aldose (Aldehyde Sugar) Ketose (Ketone Sugar) Pentoses: 5-carbon sugars (C5H10O5) Ribose Ribulose © 2015 Pearson Education Ltd Figure 5.3c Aldose (Aldehyde Sugar) Ketose (Ketone Sugar) Hexoses: 6-carbon sugars (C6H12O6) Glucose Galactose Fructose © 2015 Pearson Education Ltd  Monosaccharides are often drawn as linear skeletons; yet, many form rings in aqueous solutions © 2015 Pearson Education Ltd Figure 5.4 (a) Linear and ring forms (b) Abbreviated ring structure © 2015 Pearson Education Ltd  Sugars a) Monosaccharides b) Disaccharides c) Polysaccharides © 2015 Pearson Education Ltd 27  Sugars: Disaccharides A disaccharide is formed when a dehydration reaction joins two monosaccharides This covalent bond is called a glycosidic linkage © 2015 Pearson Education Ltd Figure 5.5 (a) Dehydration reaction in the synthesis of maltose (malt sugar) 1−4 glycosidic linkage H2 O Glucose Glucose Maltose Used in brewing beer (b) Dehydration reaction in the synthesis of sucrose (table sugar) 1−2 glycosidic linkage Glucose H2 O Fructose Sucrose © 2015 Pearson Education Ltd  On acidic or enzymatic (lactase) hydrolysis lactose gives equimolar amounts of glucose and galactose. Since lactose is hydrolysed only by lactase(identical with emulisin) the two monosaccharide units are linked through beta –glycosidic linkage. This is also indicated by its low specific rotation. © 2015 Pearson Education Ltd  Sugars a) Monosaccharides b) Disaccharides c) Polysaccharides © 2015 Pearson Education Ltd 31  Polysaccharides Polysaccharides, the polymers of sugars, have storage and structural roles The architecture and function of a polysaccharide are determined by its sugar monomers and the positions of its glycosidic linkages © 2015 Pearson Education Ltd  Polysaccharides Types of polysaccharides: – Storage polysaccharides – Structural polysaccharides © 2015 Pearson Education Ltd 33  Polysaccharides Types of polysaccharides: – Storage polysaccharides – Structural polysaccharides © 2015 Pearson Education Ltd 34  Storage Polysaccharides Starch, a storage polysaccharide of plants, consists of glucose monomers Plants store starch as granules within chloroplasts and other plastids The simplest form of starch is amylose © 2015 Pearson Education Ltd Figure 5.6a Storage structures (plastids) Amylose Glucose containing starch granules (unbranched) monomer in a potato tuber cell Amylopectin (slightly branched) 50 µm (a) Starch © 2015 Pearson Education Ltd  Glycogen is a storage polysaccharide in animals Glycogen is stored mainly in liver and muscle cells Hydrolysis of glycogen in these cells releases glucose when the demand for sugar increases © 2015 2017 Pearson Education Education,Ltd Inc. Figure 5.6b Glycogen granules Glycogen stored in muscle (extensively branched) tissue 1 µm (b) Glycogen © 2015 Pearson Education Ltd  Polysaccharides Types of polysaccharides: – Storage polysaccharides – Structural polysaccharides © 2015 Pearson Education Ltd 39  Structural Polysaccharides The polysaccharide cellulose is a major component of the tough walls of plant cells © 2015 Pearson Education Ltd  Some hydroxyl groups on the monomers of cellulose can hydrogen-bond with hydroxyls of parallel cellulose molecules © 2015 Pearson Education Ltd  Structural Polysaccharides Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ The difference is based on two ring forms for glucose: alpha (α) and beta (β) © 2015 Pearson Education Ltd © 2015 Pearson Education Ltd © 2015 Pearson Education Ltd  – Starch (α configuration) is largely helical – Cellulose molecules (β configuration) are straight and unbranched © 2015 2017 Pearson Education Education,Ltd Inc.  Enzymes that digest starch by hydrolyzing  linkages can’t hydrolyze  linkages in cellulose The cellulose in human food passes through the digestive tract as “insoluble fiber” Some microbes use enzymes to digest cellulose Many herbivores, from cows to termites, have symbiotic relationships with these microbes © 2015 Pearson Education Ltd  Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods Chitin also provides structural support for the cell walls of many fungi © 2015 Pearson Education Ltd © 2015 Pearson Education Ltd © 2015 Pearson Education Ltd  Polysaccharides 1. Starch (Plants) 2. Glycogen (animals) Storage 3. Cellulose (Plants) 4. Chitin (arthropods and Fungi) N-acetyl glucoseamine Glucose in 1, 2 and 3, but in cellulose Beta glucose Cellulose and Chitin are structural polysaccharides © 2015 Pearson Education Ltd