Biol 150 1st Edition Current Lecture Lecture 5 Genes Large organic molecules have complex shapes that are maintained by ionic hydrogen and hydrophobic interactions Molecules are composed of two or more atoms linked by chemical bonds Organic molecules are composed of carbon oxygen and hydrogen atoms linked together by covalent bonds Genes DNA RNA l Determine structure of proteins Determine when and what proteins are made gene regulation Proteins Linear chains of amnio acids linked by covalent bonds peptide bonds Why is life as we know and can imagine it based on carbon The major organic molecules that form life include proteins nucleic acids carbohydrates and lipids All are formed by specific arrangements of C H O and with nucleic acids and proteins N We ll Review the structures and some properties of these molecules Show how they are specifically assembled How they make a cell work i e live These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute H O l ll H2N C C OH Amino l Group R carboxyl group 20 amino acids that assemble to form protein All cells use just 20 different amino acids Amino acids are synthesized in cells by biochemical pathways associated with metabolism These are L a amino acids coded for by DNA Protein functions and locations in a cell are due to the location of the amino acids and their functional R groups in the protein Primary 1 protein structure The unique sequence of amino acids in a polypeptide The selection of specific amino acid and the sequence in which the amino acids are assembled is specified by genes which are sequences of nucleotides in a DNA molecule Amino acids are linked by covalent peptide bonds H R l O l ll H N C C OH H N R l l O H N C OH H2O between the two H 1 structure sequence of specific amino acids held together by covalent peptide bonds H bonds ionic interactions hydrophobic interactions 1st amino acid made during protein synthesis amino terminus Once amino acids are assembled in a single chain the chain is folded to form the protein into a specific shape that allows it to interact with other proteins The final shape of the protein is maintained by ionic hydrogen and hydrophobic interactions among the side chains Nucleic acids DNA and RNA a DNA RNA composed of a strand of nucleotides linked by covalent bonds