Chapter 3 1 3 4 and 4 1 Notes Section 3 1 1 2 3 4 Four molecules that make up living things Proteins Formed by 20 amino acids Carbohydrates Similar sugar monomers linked together chemically to form polysaccharides Lipids Lipid monomers maintaining interaction by non covalent forces Nucleic acids Formed from four kinds of nucleotide monomers linked together in long chains POLYMERS A large molecule made up of similar or identical subunits called monomers Proteins carbs and nucleic acids MONOMERS A small molecule two or more of which can be combined to form oligomers or polymers MACROMOLECULES Polymers with molecular weights exceeding 1 000 Proteins carbs and nucleic acids FUNCTIONAL GROUPS A combination of atoms that contributes specific properties when attached to larger molecules ISOMERS Molecules that have the same chemical formula but with the atoms arranged differently STRUCTURAL ISOMERS Differ in how their atoms are bonded CIS TRANS ISOMERS Typically a double bond between two carbon atoms where the carbons share two pairs of electrons Same side cis isomer Opposite side trans isomer OPTICAL ISOMERS Occur when a carbon atom has four different atoms or groups of atoms attached to it CONDENSATION REACTIONS A chemical reaction in which two molecules become connected by a covalent bond and a molecule of water is released HYDROLYSIS REACTION A chemical reaction that breaks a bond by inserting the components of water The opposite of a condensation reaction Section 3 2 PROTEIN Long chain polymer made up of 20 amino acids in different proportions and sequences POLYPEPTIDE CHAINS Unbranched polymers of covalently linked amino acids that make up a protein AMINO ACID An organic compound containing both NH2 and COOH groups R GROUP SIDE CHAIN The distinguishing group of atoms of a particular amino acid PEPTIDE LINKAGE PEPTIDE BOND The bond between amino acids in a protein Formed between a carboxyl group and an amino group with the loss of water molecules PRIMARY STRUCTURE The specific sequence of amino acids in a protein SECONDARY STRUCTURE Regular repeated spatial patterns in different regions of a polypeptide chain ALPHA HELIX A prevalent type of secondary protein structure a right handed spiral BETA PLEATED SHEET A type of protein secondary structure resulting from hydrogen bonding between polypeptide regions running antiparallel to each other TERTIARY STRUCTURE The relative locations in three dimensional space of all the atoms in the molecule the overall shape of a protein DENATURED Loss of activity of an enzyme or nucleic acid molecule as a result of structural changes induced by heat or other means QUATERNARY STRUCTURE The specific three dimensional arrangement of protein subunits Two situations in which polypeptide chains are in danger of binding the wrong substance 1 Just after a protein is made 2 Following denaturation CHAPERONES A special class of proteins present in most cells that protect the three dimensional structures of other proteins Section 3 3 CARBOHYDRATES Organic compounds containing carbon hydrogen and oxygen in the ratio 1 2 1 Sugars starch cellulose etc Three major biochemical roles 1 A source of stored energy that can be released in a form usable by organisms 2 Used to transport stored energy within complex organism 3 Serve as carbon skeletons that can be rearranged to form new molecules 1 2 3 4 Four categories MONOSACCHARIDES A simple sugar made up of one monomer DISACCHARIDES Consists of two monosaccharides linked together by covalent bonds OLIGOSACCHARIDES Made up of several monosaccharides POLYSACCHARIDES Polymers made up of hundreds or thousands of monosaccharides GLUCOSE A monosaccharide in all living cells used as an energy source PENTOSES A sugar containing five carbon atoms HEXOSE A sugar containing six carbon atoms GLYCOSIDIC LINKAGE Bond between carbohydrate molecules through an intervening oxygen atom STARCHES A polymer of glucose used by plants to store energy GLYCOGEN A water insoluble highly branched polymer of glucose used by animals to store energy Section 3 4 LIPIDS Hydrocarbons that are insoluble in water because of their many non polar covalent bonds TRIGLYCERIDES A simple lipid in which three fatty acids are combined with one molecules of glycerol FATS Triglycerides that are solid at room temperature OILS Triglycerides that are liquid at room temperature GLYCEROL A small molecule with three hydroxyl groups that make up triglycerides FATTY ACID A long non polar hydrocarbon chain and an acidic polar carboxyl group that makes up a triglyceride AMPHIPATHIC A molecule having both hydrophilic and hydrophobic regions PHOSPHOLIPIDS A lipid containing a phosphate group an important constituent of cellular membranes BILAYER A sheet two molecules thick with water excluded from the core Section 4 1 NUCLEIC ACIDS Polymers specialized for the storage transmission and use of genetic information DNA A macromolecule that encodes hereditary information and passes it from generation to generation RNA An often single stranded nucleic acid whose nucleotides use ribose rather than deoxyribose and in which the base uracil replaces thymine found in DNA NUCLEOTIDE The basic chemical unit in nucleic acids consisting of a pentose sugar a phosphate group and a nitrogen containing base 1 BASE The purine or pyrimidine that is attached to each sugar in the sugar phospahte backbone 2 Pentose sugar 3 1 3 phosphate groups NUCLEOSIDES Molecules consisting of a pentose sugar and nitrogenous base but no phosphate group The bases of the nucleic acids take one of two chemical forms 1 PYRIMIDINE A six membered single ring structure 2 PURINE A fused double ring structure DEOXYRIBOSE A five carbon sugar found in nucleotides and DNA RIBOSE A five carbon sugar in nucleotides and RNA PHOSPHODIESTER LINKAGE The connection in a nucleic acid strand formed by linking two nucleotides Four bases are found in DNA 1 ADENINE A 2 CYSTOSINE C 3 GUANINE G 4 THYMINE T Four bases are found in RNA 1 ADENINE A 2 CYSTOSINE C 3 GUANINE G 4 URACIL U COMPLEMENTARY BASE PAIRING The base pairing of T A and C G in DNA The base paring of A U and C G in RNA DOUBLE HELIX The coil configuration of two complementary antiparallel strands DNA transfers information in two ways 1 DNA REPLICATION The creation of a new strand of DNA in which DNA polymerase catalyzes the exact reproduction of an existing strand of DNA 2 GENE EXPRESSION The overall process of transcription and translation TRANSCRIPTION The synthesis of RNA