BIO2 Proteins: Fundamentals of Biology - Lecture Slides PDF

13/01/2025 OBJECTIVES  describe what is a protein and identify its major functions;...

13/01/2025 OBJECTIVES  describe what is a protein and identify its major functions;  determine the basic structure of amino acids;  explain the importance of the variable R group;  identify the four levels of protein structure; Jerzon G. Villacencio  discuss how the levels of protein structure are achieved and the Consultation Time: 2:00 - 4:00 PM WF significance of these structures to protein function; and  determine how enzyme concentration, substrate concentration, temperature and pH affect the rate of enzyme-mediated reactions Department of Science and Technology Philippine Science High School 10/01/2025 2023 | Villacencio, Jerzon G. 443 CENTRAL VISAYAS CAMPUS 442 443 PROTEIN FUNCTIONS PROTEIN FUNCTIONS 1 2 3 4 5 6 10/01/2025 2023 | Villacencio, Jerzon G. 444 10/01/2025 2023 | Villacencio, Jerzon G. 445 444 445  13/01/2025 1. Transport 2. Structural support - Transport proteins in cell membrane; hemoglobin  Keratin  Collagen 10/01/2025 2023 | Villacencio, Jerzon G. 446 10/01/2025 2023 | Villacencio, Jerzon G. 447 446 447 3. Defense 4. Movement actin & myosin fibers (muscle) Antibody/ immunoglobulin 10/01/2025 2023 | Villacencio, Jerzon G. 448 10/01/2025 2023 | Villacencio, Jerzon G. 449 448 449  13/01/2025 5. Storage 6. Regulation Insulin -regulates blood sugar Hyperglycemia - too high Hypoglycemia - too low 10/01/2025 2023 | Villacencio, Jerzon G. 450 10/01/2025 2023 | Villacencio, Jerzon G. 451 450 451 PROTEIN FUNCTIONS PROTEIN Amino acids Polypeptide Protein chain General structure of an amino acid Monomer: Amino acid What is a protein? Bond: Peptide bond What is an amino acid? 10/01/2025 2023 | Villacencio, Jerzon G. 452 10/01/2025 2023 | Villacencio, Jerzon G. 453 452 453  13/01/2025 QUESTION QUESTION Upon chemical analysis, a particular polypeptide was found to At which bond would water need to be added to achieve contain 100 amino acids. How many peptide bonds are present in hydrolysis of the peptide, back to its component amino acid? this protein? a. 101 b. 100 c. 99 d. 98 10/01/2025 2023 | Villacencio, Jerzon G. 454 10/01/2025 2023 | Villacencio, Jerzon G. 455 454 455 Amino acid types: Nonpolar/Hydrophobic Amino acid types: Polar/Hydrophilic contain aliphatic (hydrocarbon) chains or  Contain electronegative atoms as R group but they do not act as acids or aromatic rings bases thus they don’t donate or accept protons or H+ uncharged at physiological pH incapable of participating in hydrogen bonding 10/01/2025 2023 | Villacencio, Jerzon G. 456 10/01/2025 2023 | Villacencio, Jerzon G. 457 456 457  13/01/2025 Formation of the Amino Acid Chain Amino acid types: Electrically charged linked together by peptide bonds - Contain electronegative atoms as R the amine group of one AA connects to the carboxyl group of the other AA group that act as acids or bases through a dehydration synthesis reaction because they donate or accept protons or H+ - Basic (+) or acidic (-) - All polar 10/01/2025 2023 | Villacencio, Jerzon G. 458 10/01/2025 2023 | Villacencio, Jerzon G. 459 458 459 Hydrolysis & Dehydration Synthesis LEVELS OF PROTEIN STRUCTURAL ORGANIZATION 10/01/2025 2023 | Villacencio, Jerzon G. 460 460 461  13/01/2025 Polypeptides fold up into proteins Primary and secondary structure  A chain of amino acids folds into a unique 3-D shape to become a protein.  The function of a protein depends on its shape, or tertiary structure.  Denatured proteins lose their shape. Protein is functional Protein is nonfunctional 462 463 α Helix  Hydrogen bonds form between the oxygen of the C=O of each peptide bond in the strand (intra-strand) and the hydrogen of the N-H group of the peptide bond. Hydrogen bond 10/01/2025 2023 | Villacencio, Jerzon G. 465 464 465  13/01/2025 Tertiary structure β Sheet The beta (β) strand or amino acid chain - 3D shape of a polypeptide, resulting from interactions between the side zigzags in a flat plane, forming a sheet chains (R groups) of the various amino acids hydrogen bonding in a ß-sheet is between strands (inter-strand) rather than within strands (intra-strand) H-bond Hydrogen bonds stabilize the sheet Disulfide linkages Ionic bond Hydrophobic interaction Hydrogen bond 10/01/2025 2023 | Villacencio, Jerzon G. 466 10/01/2025 2023 | Villacencio, Jerzon G. 467 466 467 Quaternary Structure SUMMARY - presence and arrangement of two or more polypeptide chains  Chaperonin- promote correct association of the individual amino acid chains and inhibit incorrect formations Hemoglobin structure 10/01/2025 2023 | Villacencio, Jerzon G. 468 10/01/2025 2023 | Villacencio, Jerzon G. 469 468 469  13/01/2025 Assessment Alzheimer's Disease (AD) Altering which of the following levels of structural organization - Brain plaques called β-amyloid proteins could change the function of a protein? - deterioration of thought processes (death of brain cells) - Caused by protein misfolding A) primary & secondary B) tertiary C) quaternary D) all of the above 10/01/2025 2023 | Villacencio, Jerzon G. 470 10/01/2025 2023 | Villacencio, Jerzon G. 471 470 471 Cystic Fibrosis (CF) Cystic Fibrosis (CF) - production of thick, sticky mucus that clogs the lungs - cystic fibrosis transmembrane conductance regulator (CFTR) protein helps to maintain the balance of salt and water on many surfaces in the body, such as the surface of the lung Mutated CFTR gene 10/01/2025 2023 | Villacencio, Jerzon G. 472 10/01/2025 2023 | Villacencio, Jerzon G. 473 472 473  13/01/2025 MEMBRANE PROTEINS STRUCTURAL SUPPORT Histone - protein that provides structural support to a chromosome. Cell Membrane Integral Peripheral Proteins Proteins 10/01/2025 2023 | Villacencio, Jerzon G. 474 10/01/2025 Nucleus 2023 | Villacencio,Histones Jerzon G. 475 474 475 PROTEINS - carbon, hydrogen, oxygen, nitrogen, sulfur - the “workers” of cells 10/01/2025 2023 | Villacencio, Jerzon G. 477 476 477