MCB 150 1st Edition Lecture 5 Outline of Last Lecture I Types of monosaccharides a Hexoses b Trioses c Pentoses II Polysaccharides a Cellulose b Starch c Glycogen Outline of Current Lecture III Introduction to Proteins IV Amino Acid Properties V Structures a Primary b Secondary c Tertiary d Quaternary Current Lecture Introduction to Proteins Proeomics the study of protein and protein activity we are the products of our proteins and our protein functions Proteins make up the biggest portion in the composition of macromolecules in a cell Uses of Protein Movement Actin and Myosin in muscle tissues Defense Antibodies aid the immune system Structure Keratin in hair Transport Hemoglobin transports oxygen to tissues Signaling Glucagon signals blood sugar levels Catalysis regulation metabolism Largest roles of Proteins 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 Most of our genetic information are used as blueprints to making proteins Amino Acids monomers of proteins everyone has an amino group a carboxyl group and a hydrogen Only difference is the side chain Peptide bond bond that forms between amino acids through the process of condensation Condensation Amino group of incoming with the carboxyl of the existing group Molecule of water is lost and a covalent bond is formed Amino Acid Properties 20 amino acids that are found in proteins Their only difference is the R groups giving each amino acid certain properties Because there are so many there can be a huge number of different amino acid sequences ex Tripeptide has 8 000 possibilities Most proteins contain more than 100 amino acids Classifying amino acid R groups Uncharged polar Uncharged nonpolar Positively charged basic Negatively charged acidic Polar amino acids all have an oxygen in the side chains Nonpolar amino acids most side chains are carbon and hydrogen Structures Proteins can be found in infinite numbers of 3D conformations This confirmation is critical to the proteins function If a protein is folded incorrectly it can cause complications like Alzheimer s Parkinson s etc Primary Structure 1 Linear sequence from N C All proteins have a unique primary structure Secondary structure 2 First level of folding Stabilized by hydrogen bonds in between the peptide linkages Peptide backbone is polar Independent of R groups and found n most proteins Coil form helix sheet formed pleated Tertiary structure 3 Folded 3D shape that is totally unique Final confirmation of some proteins Due to interactions between r groups with both each other and the backbone Stabilized by o H bonds between polar side chains o H bonds between hydrophilic side chains and backbone o Ionic bond between an acidic and a basic amino acid o Hydrophobic clustering of non polar side chains o Van der Waals forces o Disulfide linkages Quaternary structure 4 Found in proteins with multiple subunits Subunits can be the same homodimer or different heterodimer