Chapter 4 - Biological Molecules (Part 1) PDF

CHAPTER 4 BIOLOGICAL MOLECULES [PREPARED BY MADAM HAJAR ALSHURDIN]  TABLE OF CONTENTS 4.1 Functional Groups 4.2 Macromolecules 4.3 Carbohydrates 4.4 Lipids 4.5 Proteins...

CHAPTER 4 BIOLOGICAL MOLECULES [PREPARED BY MADAM HAJAR ALSHURDIN]  TABLE OF CONTENTS 4.1 Functional Groups 4.2 Macromolecules 4.3 Carbohydrates 4.4 Lipids 4.5 Proteins 4.6 Nucleic Acids | by HAJAR ALSHURDIN  CONTENT CHAPTER 4 4.1 Functional groups 4.5 Proteins Hydroxyl, carbonyl, carboxyl, amino, Amino acids, peptide formation, sulfhydryl, phosphate, methyl polypeptide chains, levels of protein 4.2 Macromolecule (Basic processes – structure, (primary/ secondary/ condensation & hydrolysis) tertiary/ quaternary), protein 4.3 Carbohydrates denaturation and renaturation Monosaccharides, disaccharides and 4.6 Nucleic acids polysaccharides Functions of nucleic acids, 4.4 Lipids nucleotides, bases. Fatty acids and glycerol Introduction to double helix structure Simple lipids (steroids, (Watson-Crick model) prostaglandins), Complex lipids Types of RNA and functions (mRNA, (triacylglycerol, phospholipids, tRNA, rRNA) sphingolipids, waxes)  LESSON OUTCOMES 01 describes the importance of functional groups to organic molecules 02 identify the biological macromolecules with its physical and chemical properties classify the physiological roles of 03 biological macromolecules and its examples | by HAJAR ALSHURDIN  BIOLOGICAL MOLECULES ❑ Organisms (animals and plants) are made up of chemicals that are based mostly on the element carbon. ❑ Properties of organic molecule depends on the arrangement of carbon skeleton and functional groups attached to the skeleton. ❑ Most organic molecules consist of carbon chains; carbon bonded to carbon or to other molecules. ❑ Carbons can form up to 4 covalent bonds. | by HAJAR ALSHURDIN  BIOLOGICAL MOLECULES ❑ The variation in carbon skeletons ❑ May bond with functional groups with specific properties. | by HAJAR ALSHURDIN 4.1 FUNCTIONAL GROUPS | by HAJAR ALSHURDIN  Functional Groups Definition: Groups of atoms that occur within organic molecules and give specific chemical properties to those molecules. Location: Can be found along the "carbon backbone" of macromolecules Play an important role in the formation of molecules like DNA, proteins, carbohydrates, and lipids. These functional groups can affect in: ❑ Chemical reactions ❑ Molecular shape & structure ❑ Specific properties (function) | by HAJAR ALSHURDIN  Functional Groups ❑ Formed by chains and/or rings of carbon atoms with the occasional substitution of an element such as nitrogen or oxygen. ❑ Molecules with other elements in their carbon backbone are substituted hydrocarbons. ❑ When functional groups are shown, the organic molecule is sometimes denoted as "R”. In order to condense the structure and focus on the hydroxyl group the oxygen and hydrogen bound to the second carbon (in figure), everything besides the hydroxyl group will be replaced with an R. | by HAJAR ALSHURDIN  The are seven (7) functional groups that are most important in the biological processes. hydroxyl carbonyl (-OH) (C=O) carboxyl Function amino (-COOH) (-NH2) al Groups phosphate sulfhydryl (-OPO32-) (-SH) methyl (-CH3) | by HAJAR ALSHURDIN  Properties of Functional Groups ❑ All seven functional groups can be chemically reactive. ❑ Usually classified as hydrophobic or hydrophilic depending on their charge or polarity. ✔ Hydroxyl group ✔ Carbonyl group ✔ Carboxyl group HYDROPHILIC ✔ Amino group ✔ Phosphate group ✔ Sulfhydryl group ✔ Methyl group HYDROPHOBIC | by HAJAR ALSHURDIN  Properties of Functional Groups ❑ Hydrophobic functional group ❑ The non-polar methane molecule (methyl group). ❑ Hydrophilic functional groups ❑ Carboxyl group ionizes to release hydrogen ions (H+) from the COOH group resulting in the negatively charged COO- group; this contributes hydrophilic nature of whatever molecule it is found on. ❑ found in amino acids and on fatty acid heads that form triglycerides and phospholipids. ❑ Carbonyl group, have a partially negatively charged oxygen atom that may form hydrogen bonds with water molecules, again making the molecule more hydrophilic. | by HAJAR ALSHURDIN  HYDROXYL GROUP (-OH) ❑ Hydrogen atom bind covalently with oxygen atom, forming a polar covalent bond to the carbon skeleton. (C-OH) ❑ Due to polar covalent bonds, hydroxyl groups improve the solubility of organic molecules. ❑ Organic compounds with hydroxyl groups are ALCOHOLS and their names typically end with -ol. | by HAJAR ALSHURDIN  CARBONYL GROUP (C=O) ❑ An oxygen atom joined to the carbon skeleton by a double bond. ❑ If the position of carbonyl group is on the end of the carbon skeleton, the compound is an ALDEHYDE. ❑ If the position of carbonyl group is on the middle of the carbon skeleton, the compound is a KETONE. | by HAJAR ALSHURDIN  CARBOXYL GROUP (-COOH) ❑ Carbon atom form a double bond with an oxygen atom and a single bond to a hydroxyl group. ❑ Compounds with carboxyl groups are CARBOXYLIC ACIDS. ❑ because acid can donate up a hydrogen ion (H+). ❑ Carboxyl group acts as an acid. | by HAJAR ALSHURDIN  AMINO GROUP (-NH2) ❑ Nitrogen atom attached to two hydrogen atoms and the carbon skeleton. ❑ Organic compounds with amino groups are AMINES. Amino acids, the ❑ The amino group acts as base. building blocks of ❑ because ammonia can pick up a hydrogen proteins, have amino and carboxyl groups. ion (H+) from the solution. | by HAJAR ALSHURDIN  SULFHYDRYL GROUP (-SH) ❑ Sulfur atom bonded to a hydrogen atom and to the backbone. ❑ Organic molecules with sulfhydryl groups are THIOLS. ❑ Sulfhydryl groups help stabilize the structure of proteins. ❑ Eg: amino acid Cysteine | by HAJAR ALSHURDIN  PHOSPHATE GROUP (-OPO32-) ❑ Phosphorus bound to four oxygen atoms (three with single bonds and one with a double bond). ❑ Phosphate groups are ANIONS with two negative charges. ❑ Organic compound with phosphate group is Organic phosphate. ❑ One function of phosphate groups is to transfer energy between organic molecules. | by HAJAR ALSHURDIN  METHYL GROUP (-CH3) ❑ Contain a carbon atom surrounded by three hydrogen atoms. ❑ Organic compounds with methyl groups are Methylated compounds. ❑ Fats, oils, waxes, hormones. ❑ Ability to form non-polar covalent bonds and hydrophobicity. ❑ Acts as a recognizable tag on biological molecules. ❑ Functions of methyl groups are: ❑ affects the expression of genes when bonded to DNA or to proteins that bind to DNA ❑ affects the shape and function of male and female sex hormones. Methyl Methylated | by HAJAR ALSHURDIN Summary of Functional Groups | by HAJAR ALSHURDIN Brainstorming A A S C P A Q R A B Z O X X L Y F L R A P H L U I L I T E R J N O Let's go! O N E D Y H E D L I S H P R C S S O Y Y O P There are 10 words O E N O T E K H O N H related to functional groups. C V P H O N I F E T A Can you find all of them? L L D T H I O L L H T A Y D R Y M J U S I E W A B A S A E S K L A C I L I H P O R D Y H | by HAJAR ALSHURDIN 4.2 MACROMOLECULES [PREPARED BY MADAM HAJAR ALSHURDIN]  Organic Compound Chemical compounds that contain carbon (C) originate from living things Carbohydrates 1 Proteins 3 2 Lipids 4 Nucleic Acids | by HAJAR ALSHURDIN  Important Terms MONOMER POLYMER LARGER POLYMER Small, simple molecules Larger molecules that Macromolecules that are linked together to formed by combination form larger molecules. of monomers. | by HAJAR ALSHURDIN CONDENSATION & HYDROLYSIS REACTION | by HAJAR ALSHURDIN CONDENSATION / DEHYDRATION Chemical process by which 2 molecules (monomers) are JOINED together to make a larger, more complex molecule (polymers) with the loss of water. It is the basis for the SYNTHESIS of all the important biological macromolecules (carbohydrates, proteins, lipids, nucleic acids) from their monomers. AH + BOH --> AB + H2O | by HAJAR ALSHURDIN CONDENSATION / DEHYDRATION CONDENSATION / DEHYDRATION EXAMPLE Formation of the disaccharide maltose from 2 glucose molecules. 2 glucose molecules are A disaccharide is produced by In maltose, a glycosidic bond COMBINED using a joining 2 monosaccharide is formed between opposite condensation reaction, (single sugar) units. sides of the 2 glucose units with the removal of water. Glucose Glucose Maltose | by HAJAR ALSHURDIN  Opposite reaction HYDROLYSIS to condensation. A large molecule (polymer) is SPLIT into smaller sections (monomer) by breaking a bond, adding -H to one section and -OH to the other. Since it involves the addition of water, this explains why it is called hydrolysis, meaning splitting by water. AB + H2O --> AH + BOH | by HAJAR ALSHURDIN HYDROLYSIS  HYDROLYSIS EXAMPLE Digestion of the disaccharide maltose forming 2 glucose molecules. 2 glucose molecules are The enzyme maltase efficiently Water is a participant in the process, SPLIT using a hydrolysis catalyses the hydrolysis of maltose adding -H and -OH groups either reaction, with the addition into 2 glucose molecules. side of the glycosidic bond. of water. Maltose Glucose Glucose | by HAJAR ALSHURDIN  A whole view of MACROMOLECULES | by HAJAR ALSHURDIN  Brainstroming Let's go! True or False using mentimeter True or False Questions The process of removing water in order to form a bond between 1 True False monomers is called condensation The process of breaking the bonds within a starch molecule in 2 True False order to release glucose molecules is called dehydration Hydrolysis is where a process breaking up the linkage with 3 True False addition of water molecule https://www.menti.com/alha1gsdiqd7 Code: 6640 1926 | by HAJAR ALSHURDIN 4.3 CARBOHYDRATES [PREPARED BY MADAM HAJAR ALSHURDIN] Properties 01 Large group of organic compounds. Also called as saccharides / sugar. C HO Containing the elements carbon, 02 hydrogen, oxygen. Has carbonyl group, and multiple hydroxyl groups. Produced through photosynthesis by 03 green plants and bacteria. Empirical formula (CH2O)n 04 Elemental composition Cx(H2O)y Where, y = 3,4,5,6,7 Consist of sugar, glycogen, starch 05 and cellulose. | by HAJAR ALSHURDIN Functions of Carbohydrate Sugar Glycogen provide an accessible source and store of provide energy energy in human & source and animals. energy storage in human & animals. Starch Cellulose Common as food storage in plant. Important materials of cell wall for structural support in plant. Fibre in the human diet. | by HAJAR ALSHURDIN  Classification of Carbohydrates MONOSACCHARIDE POLYSACCHARIDE DISACCHARIDE | by HAJAR ALSHURDIN  Classification of Carbohydrates Monosaccharide Disaccharide Polysaccharide Hundreds of Simple sugar Combination of monosaccharides 2 monosaccharides join together forming a long chain Glucose Maltose Starch Fructose Sucrose Glycogen Galactose Lactose Cellulose | by HAJAR ALSHURDIN  MONOSACCHARIDES | by HAJAR ALSHURDIN Chemical Properties Terminology Sweet Greek- mono = single, Solid crystalline saccharum = sugar Low molecular mass Soluble in water Example (CH2O)n Glucose Fructose Description Galactose Simplest carbohydrates, Classification cannot be further n= 3 (triose) hydrolyzed Also classified based on n= 4 (tetrose) All are reducing sugar number of carbon backbone n= 5 (pentose) ? & position of carbonyl group n= 6 (hexose) ? MONOSACCHARIDES 4 1 4 1 3 2 3 2 Hexose (6 carbons) Galactose is differed from glucose due to the way the -OH is located in the 4th carbon. When both combine, it forms disaccharide lactose. | by HAJAR ALSHURDIN  Glucose Galactose Molecular formula C6H12O6 C6H12O6 Molar mass 180.16 g mol−1 180.156 g mol−1 Glucose can exist in both Galactose can exist in both open chain and cyclic form. open chain and cyclic form. Structure It has five hydroxyl groups that are In the open chain form, galactose has as a arranged in a specific way along the six- carbonyl at the end of the chain. carbon backbone. It has four isomers. Gums, sugar beets, dairy products, gums Sources Juices, fruits, sugars, etc. and mucilage. α-D-glucose: 146 °C Melting point β-D-glucose: 150 °C 167 °C, 440 K, 333 °F Galactose cannot be easily broken down. Glucose is broken down in the body and Broken down then used as body fuel and energy. It is goes through the Leloir pathway in the body. | by HAJAR ALSHURDIN Carbohydrates have a carbonyl group and multiple hydroxyl groups. The position of carbonyl group determine the type of sugar. (positional isomer) ALDOSE KETOSE The position of carbonyl The position of carbonyl group is at the end of group in the middle of carbon backbone carbon backbone | by HAJAR ALSHURDIN  DISACCHARIDES Chemical Properties Terminology Small, Sweet Greek- di = double, Solid crystalline saccharum = sugar Soluble in water Example C12H22O11 Maltose Sucrose Description Lactose Consist of two Reaction monosaccharides linked Molecules of water is removed via GLYCOSIDIC BOND Reversed reaction (breakdown) (C-O-C) by condensation is called hydrolysis | by HAJAR ALSHURDIN  DISACCHARIDES Formation Reaction Source & Function Malt sugar in germinating barley glucose + glucose Maltose + water grains Sugar-cane; main sugar form that glucose + fructose Sucrose + water is transport in plants. Milk sugar; found in the milk of glucose + galactose Lactose + water mammals; source of energy | by HAJAR ALSHURDIN DISACCHARIDES Formation Reaction + H2O H2O Glycosidic bond CONDENSATIO The bond linking the two monosaccharide N to form disaccharide | by HAJAR ALSHURDIN  + H2O H + H2O + H2O | by HAJAR ALSHURDIN  Reducing & Non-reducing Sugar Reducing sugar Sugar which can reduce Cu2+ ion into Cu+ blue colour in Benedict solution will turn to brick red colour after heating Monosaccharides Reducing sugar Maltose Lactose Sucrose Non-reducing sugar | by HAJAR ALSHURDIN  POLYSACCHARIDES Description Chemical Properties Combination of many Large monosaccharide Not sweet (more than two) by Insoluble in water condensation Example Cx(H2O)y Cellulose Starch storage Glycogen polysaccharides Structure Other variable in length, branched or unbranched, Modified glucose for structural folded, straight or coiled polysaccharides Peptidoglycan (bacterial cell wall) Chitin (fungal cell wall & exoskeleton of| byinsects) HAJAR ALSHURDIN  POLYSACCHARIDES | by HAJAR ALSHURDIN Starch Cellulose Glycogen Amylose Amylopectin Composition β-glucose α-glucose α-glucose α-glucose Composed 2000-200,000 2000-3000 glucose 200-1500 glucose 2,000-120,000 glucose subunits glucose Long straight chain, thin Long straight chain, Structure Parallel linked via Branches Branches folded hydrogen bond (stable) Shape Structural component Energy storage Function - elements of cell wall Energy storage of glucose in plants - stored in liver and muscle in in plants animal POLYSACCHARIDES Chitin Derivative of carbohydrate Chitin is a naturally occurring polysaccharide existing in arthropods; the outer shells of crustaceans, insect exoskeletons. It also can be found in fungal cell walls. It is the second most abundant natural polymer after cellulose. | by HAJAR ALSHURDIN Brainstroming Let's go! MCQ using mentimeter Identify which of the following elements that make up the 1 Carbohydrates. A Carbon and oxygen B Carbon and hydrogen C Carbon, nitrogen and oxygen D Carbon, hydrogen and oxygen https://www.menti.com/alha1gsdiqd7 Code: 6640 1926 Identify the type of chemical bond form between monosaccharides 2 to form polysaccharides. A Ionic bond B Peptide bond C Glycosidic bond D Hydrogen bond | by HAJAR ALSHURDIN  REFERENCES Main reference Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., & Minorsky, P. V. (2017). Biology: a global approach. Pearson Higher Ed. Other references Qin, Y. (2016). 3–A brief description of https://courses.lumenlearning.com/wm- textile fibers. Medical Textile Materials. biology1/chapter/functional-groups-2/ Jiaxing: Woodhead Publishing, 23-42. https://courses.lumenlearning.com/boundless- biology/chapter/synthesis-of-biological- macromolecules/ https://courses.lumenlearning.c https://courses.lumenlearning.com om/sanjacinto- /microbiology/chapter/carbohydrat biology1/chapter/synthesis-of- es/ biological-macromolecules/ https://ib.bioninja.com.au/standard-level/topic- 2-molecular-biology/23-carbohydrates-and- https://microbenotes.com/carbohydrate lipids/sugar-subunits.html s/. | by HAJAR ALSHURDIN THANK YOU Prepared & Presented by Mdm Hajar Alshurdin