Introduction to Orgo  Organic chem – the study of C based compounds (must have both C & H)  Why Carbon ?  It’s versatile!  4 valence electrons (4 covalent bonds)  Form simple or complex compounds  C chains form backbone of most biological molecules (straight, bent, double bond, rings)

Hydrocarbons  Hydrocarbons ONLY consist of C & H  Importance – store energy  Hydrophobic

Organic Shorthand

Isomers  Isomers – same number of atoms per element, different arrangement  3 types:  Structural – differ in covalent partners  Geometric – differ in arrangement around a double bond  Enantiomers – mirror images of each other  Different structure means different function!

Isomers Structural Isomers Geometric Isomers Enantiomers cis trans

Functional Groups  Functional groups – parts of organic molecules that are most commonly involved in chemical reactions  replace H in hydrocarbons  Most are hydrophilic  Variation of life is due to molecular variation

Functional Groups

Macromolecules  Huge biological molecules!  4 classes:  Carbohydrates  Lipids  Proteins  Nucleic Acids  Polymers – long molecule made of monomers

Polymerization  Building dimers or polymers  Condensation rxn AKA dehydration synthesis:  Monomer-OH + monomer-H  dimer + H 2 O  Breaking down dimers or polymers  Reverse rxn called hydrolysis  Dimer + H 2 O  monomer-OH + monomer-H

Carbohydrates  Cells get most of their energy from carbs  Carbs are sugars, most end in “ -ose ”  Multiple of molecular formula: CH 2 O  Glucose: C 6 H 12 O 6  Carbonyl group  Multiple hydroxyl groups

Carbohydrates  Monosaccharides  Monomers: simple sugars w/ 3-7 carbons  Ex. (C 6 H 12 O 6 ): Glucose, Fructose, Galactose  Disaccharide – formed by 2 monosaccharides forming a glycosidic linkage by dehydration synthesis  Ex:  glucose + glucose  maltose + H 2 O  glucose + fructose  sucrose + H 2 O  glucose + galactose  lactose + H 2 O

Carbohydrates

 Polysaccharides : 100’s – 1000’s of monosaccharides joined by glycosidic linkages  Storage polysaccharides  Starch  Plants – stored in plastids  Made entirely of glucose - helical  Glycogen  Animals – stored in liver & muscle (in vertebrates)  Made entirely of glucose - branched  Structural polysaccharides  Cellulose – plant cell walls  Made of glucose – linear  Chitin  Exoskeleton of arthropods & fungi cell walls

Lipids  No polymers!  Hydrophobic (mostly hydrocarbons)  Store energy efficiently (2x more than carbs!)  Types :  Fats & oils  Phospholipids  Steroids  Waxes

Fats & Oils  Fat = dehydration synthesis of:  Glycerol C 3 H 5 (OH) 3  Fatty acid: 16 or 18 carbon hydrocarbon chain w/ carboxyl group  Glycerol + 3 fatty acid chains = triglyceride + 3 H 2 O  Function:  Energy storage  Insulation  Protective cushioning around organs

Saturated Fats  No double bonds between carbons  Saturated with hydrogens  Solid at room temperature  Mostly animal fat  Ex: butter, lard, adipose

Unsaturated Fats  1 or more double bonds between carbons  Bent or kinked chains  Liquid at room temperature  Mostly plant or fish fat  Ex: olive oil, cod liver oil, corn oil

Phospholipids  Glycerol + 2 fatty acids + phosphate  Phosphate head = hydrophilic  Fatty acid tails = hydrophobic  Form a bilayer in water  Makes up cell membranes

Phospholipids

Steroids  4 fused carbon rings with various functional groups  Ex: cholesterol  Component of cell membrane & many hormones

Proteins  Functions: enzymes, structural support, storage, transport, cellular communication, movement, defense  Monomer = amino acid  Short C chain  Amino group  Carboxylic acid group  “R” group determines type  Cells use 20 different amino acids to build 1000’s of different proteins  Amino acids linked by peptide bonds via dehydration synthesis to form polymers – polypeptides  Chaperonins assist in protein folding

Protein Structure  1 0 Structure - Sequence of amino acids (length vary) - Determined by genes  2 0 Structure  How polypeptide folds or coils  Α helix  β pleats  3 0 Structure - 3D (fold onto itself)  H bonds  Hydrophobic interaction  Disulfide bridges  4 0 Structure – bonds to other polypeptides  2 or more polypeptide chains bonded together

Protein Conformation  Structure of a protein is directly related to function  Protein conformation is determined when it is synthesized, and it is maintained by chemical interactions  Protein conformation also depends on environmental factors: pH, salt concentration, temp…etc  Protein can be denatured – unravel and lose conformation, therefore biologically inactive.  When conditions change again, protein can be renatured (restored to normal)

Nucleic Acids  2 types:  DNA (deoxyribonucleic acid)  Found in nucleus of eukarya  Double stranded helix  Provides directions for its own replication  Also directs RNA synthesis  Though RNA controls 1 0 structure of proteins  RNA (ribonucleic acid)  Single stranded, variety of shapes  Transfers information from nucleus to cytoplasm (where proteins are made) DNA  RNA  Proteins

Structure of Nucleic Acids  Monomers – nucleotides composed of 3 parts:  Pentose (ribose or deoxyribose)  Phosphate group  Nitrogenous base  Pyrimidines – 6 membered rings of C & N  Cytosine (C)  Thymine (T)….DNA only  Uracil (U)… RNA only  Purines – 6 membered ring fused to 5 membered ring of C & N  Adenine (A)  Guanine (G)

Nucleotide Structure

Bonding of Nucleotides

ATP  Not a macromolecule, but still important for life!  Adenosine Triphosphate (ATP) – primary energy transferring molecule in the cell  ATP   ADP + P i + Energy