* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Ch. 4-5 - Carbon and Organic Chem
Survey
Document related concepts
Size-exclusion chromatography wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Point mutation wikipedia , lookup
Basal metabolic rate wikipedia , lookup
Citric acid cycle wikipedia , lookup
Metalloprotein wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Peptide synthesis wikipedia , lookup
Fatty acid synthesis wikipedia , lookup
Fatty acid metabolism wikipedia , lookup
Proteolysis wikipedia , lookup
Protein structure prediction wikipedia , lookup
Genetic code wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Transcript
CH. 4 & 5 • Chapter 4~ Carbon & The Molecular Diversity of Life • Chapter 5~ The Structure & Function of Large Molecules Why study Carbon? • All of life is built on carbon • Cells – ~72% H2O – ~25% carbon compounds • • • • carbohydrates lipids proteins nucleic acids – ~3% salts • Na, Cl, K… Chemistry of Life • Organic chemistry is the study of carbon compounds • C atoms are versatile building blocks – bonding properties – 4 stable covalent bonds H H C H H Complex molecules assembled like TinkerToys Hydrocarbons • Combinations of C & H – non-polar • not soluble in H2O • hydrophobic – stable – very little attraction between molecules • a gas at room temperature methane (simplest HC) Hydrocarbons can grow Isomers • Molecules with same molecular formula but different structures (shapes) – different chemical properties – different biological functions 6 carbons 6 carbons 6 carbons Form affects function • Structural differences create important functional significance – amino acid alanine • L-alanine used in proteins • but not D-alanine – medicines • L-version active • but not D-version – sometimes with tragic results… stereoisomers Form affects function • Thalidomide – prescribed to pregnant women in 50s & 60s – reduced morning sickness, but… – stereoisomer caused severe birth defects Diversity of molecules • Substitute other atoms or groups around the carbon – ethane vs. ethanol • H replaced by an hydroxyl group (–OH) • nonpolar vs. polar • gas vs. liquid • biological effects! ethane (C2H6) ethanol (C2H5OH) Functional groups • Parts of organic molecules that are involved in chemical reactions – give organic molecules distinctive properties hydroxyl carbonyl carboxyl • Affect reactivity amino sulfhydryl phosphate – makes hydrocarbons hydrophilic – increase solubility in water Viva la difference! • Basic structure of male & female hormones is identical – identical carbon skeleton – attachment of different functional groups – interact with different targets in the body • different effects Hydroxyl • –OH – organic compounds with OH = alcohols – names typically end in -ol • ethanol Carbonyl • C=O – O double bonded to C • if C=O at end molecule = aldehyde • if C=O in middle of molecule = ketone Carboxyl • –COOH – C double bonded to O & single bonded to OH group • compounds with COOH = acids – fatty acids – amino acids Amino • -NH2 – N attached to 2 H • compounds with NH2 = amines – amino acids • NH2 acts as base – ammonia picks up H+ from solution Sulfhydryl • –SH – S bonded to H • compounds with SH = thiols • SH groups stabilize the structure of proteins Phosphate • –PO4 – P bound to 4 O • connects to C through an O • lots of O = lots of negative charge – highly reactive • transfers energy between organic molecules – ATP, GTP, etc. Polymers – “mer” means unit – “mono” means one • Monomer-one unit – “poly” means many • Polymer-many units • Polymers are made of many monomers 19 Macromolecules •Most macromolecules are polymers, built from monomers • Four classes of life’s organic molecules are polymers – – – – Carbohydrates Proteins Nucleic acids Lipids 20 The Synthesis and Breakdown of Polymers • Monomers form larger molecules by condensation reactions called dehydration synthesis HO 1 2 3 H Unlinked monomer Short polymer Dehydration removes a water molecule, forming a new bond HO Figure 5.2A 1 H HO 2 H2 O 3 4 H Longer polymer (a) Dehydration reaction in the synthesis of a polymer 21 The Synthesis and Breakdown of Polymers • Polymers can disassemble by – Hydrolysis (addition of water molecules) HO 1 2 3 4 Hydrolysis adds a water molecule, breaking a bond HO Figure 5.2B 1 2 3 H H2 O H HO H (b) Hydrolysis of a polymer 22 Carbohydrates • MONOSACCHARIDES are simple sugars in a 1:2:1 ratio • GLUCOSE • GALACTOSE = sugar found in milk • FRUCTOSE = fruit sugar • Chemical composition (C6 H12 O6) Important Monosaccharides Glucose Carbohydrates • DISACCHARIDES consist of two single sugars(monosaccharides) linked together by glycosidic linkage (Dehydration synthesis) • Lactose = Milk sugar • Sucrose = Table sugar Carbohydrates Carbohydrates • POLYSACCHARIDE is a carbohydrate made of long chains of sugars (3 or more monosaccharides) • Starch - Plants convert excess sugars into starches for long-term storage (Alpha linkage) • Glycogen -Animals store glucose in the form of polysaccharide glycogen in the liver and muscles to be used as quick energy • Cellulose -a structural polysaccharide contained in the cell walls of plants (ß linkage) • Chitin – a polysaccharide found in the cell walls of fungi and the exoskeletons of insects and arthropods Starch Glucose Lipids • Lipids are large, NONPOLAR organic molecules that DO NOT dissolve in water • Oils, fats, waxes, and steroids are lipid based • Lipid molecules use less OXYGEN than carbohydrates to store energy efficiently • Used in biological membranes and as chemical messengers • Monomers – Fatty acids & Glycerol Lipids • UNSATURATED FATS are a liquid at room temperature (OILS). Double bonds can have hydrogen added • SATURATED FATS are solid at room temperature NO double bonds Saturated or Unsaturated Fatty Acids Stearic acid Oleic acid Liquid at room temp Solid at room temp Triacylglycerol Phospholipids – Make up the cell membrane Hydrophilic vs Hydrophobic Hydrophilic = Water loving Hydrophobic = Water fearing Steroids • Steroids – Are lipids characterized by a carbon skeleton consisting of four fused rings H3C CH3 CH3 CH3 CH3 Figure 5.15 HO 36 Proteins • • • Chemical composition C-H-O-N-S Proteins are made up of smaller monomers called AMINO ACIDS Amino Acids differ ONLY in the type of R group they carry Amino acids composed of 3 parts 1. Amino Group 2. Carboxylic group 3. R-group (Makes 20 different amino acids) Peptide Bonds – link amino acids 20 Amino Acids Protein Conformation Primary Structure – sequence of amino acids Secondary structure – Folding and coiling due to H bond formation between carboxyl and amino groups of non-adjacent amino acid. R groups are NOT involved. Tertiary structure – disulfide bridges, ionic bonding, or h-bonding of R-groups Quaternary structure – 2+ amino acid chains R- group interactions, H bonds, ionic interactions Amino Acids – – – – – – The polar uncharged amino acids are hydrophilic & can form hbonds Serine Threonine Glutamine Asparagine Tyrosine Cysteine Amino Acids The nonpolar amino acids are hydrophobic and are usually found in the center of the protein. They also found in proteins which are associated with cell membranes. – – – – – – – – – Glycine Alanine Valine Leucine Isoleucine Methionine Phenylalanine Tryptophan Proline) Amino Acids The electrically charged amino acids have electrical properties that can change depending on the pH. – – – – – Aspartic Acid Glutamic Acid Lysine Arginine Histidine Amino Acids The electrically charged amino acids (Aspartic Acid, Glutamic Acid, Lysine, Arginine, and Histidine) have electrical properties that can change depending on the pH. – Cysteine can form covalent disulfide bonds – Proline had a unique structure and causes kinks in the protein chain Denaturing of Protein Denaturing of Protein • Transfer protein from aqueous solution to an organic solvent (chloroform) • Any chemical that disrupts h-bonds, ionic bonds, & disulfide bridges • Excessive heat • Changes in pH Enzymes Act as CATALYSTS that can speed up some reactions by more than a billion times! Enzymes work by a physical fit (Lock and Key) between the enzyme molecule and its SUBSTRATE, the reactant being catalyzed. Enzymes reduces the activation energy for the chemical reaction to occur. After the reaction, the enzyme is released and is unchanged, so it can be used many times Enzyme names end in -ase Enzyme & Substrate fit like a lock & key (Shape specific) pH or temperature can change the active site shape on any enzyme Active site is where the reactants bind to the enzyme Activation Energy The energy require to start a reaction is called Activation Energy Nucleic Acids Nucleic Acids •RNA and DNA made of nucleic acids •C-H-O-N-P atoms •Polymers of nucleotides •Nucleotides consist of a 5-carbon sugar, a phosphate group, and a nitrogenous base. •Store and transmit genetic information Nucleic Acids