Transcript H - Sites
Biochemistry Proteins •Proteins= Proteios. • Elements-SONCH •diverse macromolecules •form tens of thousands of proteins •Proteins are polymers •Amino Acid monomers •Form 3-D structure, Monomer Polymer •structure always tells function Protein Examples of Functions Classes of Proteins 1. Defensive proteins=antibodies 2. Transport proteins=hemoglobin, carries oxygen 3. Signal-hormones-signal proteins which send messages to regulate metabolic processes, insulin 4. Structural- are found in the hair & fibers that make up muscles, tendons and ligaments. 5. Storage- the storage of molecules, such as the protein in white eggovalbumin & in developing seeds. 6. Contractile- fibers that enable muscles to move. http://video.google.com/videosearch?sourceid=navclient&ie=UTF8&rlz=1T4TSHB_enUS237US238&q=muscle+contraction&um=1&sa=X&oi=video_result_group&resnum=4&ct=tit le# 7. *Enzymes -are organic catalysts, which control most chemical reactions in the body •20 Different Amino Acids, •Each one different due to it’s Residue (R) group, •Some are essential and some are nonessential. hydrophilic •Some Hydrophilic •Some hydrophobic •Some are Neutral hydrophobic •Monopeptide or Amino Acid R Group=Residue •R group=residue group •chemical group that makes each Amino Acid different from one another. H Alpha Carbon Hydrogen Atom Amino Acid •Functional groups-participate in chemical reactions and give the R Group=Residue molecule it’s characteristics. •amino group •carboxyl group H Alpha Carbon Each Amino Acid has an Alpha Carbon Hydrogen Atom Each Amino Acid has an Hydrogen Atom dipeptide •Dipeptide-two Amino Acids linked A peptide bond is formed with the C in the Carboxyl group bonds to the N in the Amino group and a water molecule is formed. Peptide bond Let’s Review 1. What are the subunits of Proteins? 2. What is formed when two amino acids are linked together? 3.What specific type of bond is formed? 4. What causes this reaction to take place? 5.What is this process called? Four levels of protein • Primary Structure 1oIs the linkage (peptide bond) of Amino acids or monopeptides forming a polypeptide, 2H2O 1o •Secondary Structure 2ois the bonding between hydrogen of The amino group and the oxygen of the carboxyl group. •Secondary Structure forms •Alpha helix •Pleated sheet. Alpha helix Pleated sheet Tertiary Structure 3o, Is the combination of the Of the primary 1o And secondary 2o, Forming a 3-D structure-= globular or fibrous. Primary-1o Tertiary-3o Secondary-2o globular fibrous Tertiary Structure Has many interaction: • R groups between Amino Acids. • hydrophilic, •hydrophobic, •Hydrogen bonds •Ionic bonds •Sulfur bridges Denaturation & Renaturation of a Protein Quaternary Structure 4o Has two, three or four tertiary Structures forms a golubular structure. Examples are: enzymes, muscle, antibodies and hemoglobin. Hemoglobin the oxygen carrying molecule is globular and has four subunits, 2 alpha and 2 beta chains. BioCD Animations 5.4.1-5.4.5 Sickle Cell Anemia • The Sickle Cell allele is found in people of African, Mediterranean, & Asian decent where malaria is common. Throughout evolution people with this abnormal allele have a selective advantage over others that don’t carry this allele. Malaria Malaria is carried by a protozoan parasite-plasmodium, plasmodium is found in mosquitoes and invades red blood cells. When the parasite enters the cell it causes the cell to sickle in shape. White cells then destroy these damaged cells and not enough red cells remain for the parasite to reproduce. Malaria has kept this allele frequency higher in Africa. Origin of Sickle Cell India Zaire Angola & Nigeria Angola, Congo & Zaire Angola, Zampia, Tanzania & Zaire Gambia, Congo, Zaire & Angola Nambia, Botswana, Mozanbique, Kenya, Sudan, Libya, Algeria & Mali Sickle Cell Anemia Is an inherited genetic disease caused by a mutation in the Nucleotide sequence of DNA causing the protein molecule of Hemoglobin to change. HbAHbA homozygous HbSHbS homozygous HbAHbS heterozygous HbSHbA heterozygous Overview of Protein Synthesis •Transcription •Translation Hemoglobin CTTCAT Mutation-Base Substitute Normal Thymine -1 Thymine -1 Net negative charge -2 Thymine -1 Net negative charge -1 Using Gel Electrophoresis to Diagnose Sickle Cell Anemia (Hemoglobin) Normal Sickle Carrier Cell P1 P2 CT T CA T + Controls Known's Unknown's The change takes place in the sequence of the beta chain of Amino Acids, Glutamic acid (polar) is replaced with Valine (nonpolar), this causes a reduction in the pH causing blood to become acidic causing the abnormal hemoglobin to link and crystallize, cells deform and become sickle or crescent in shape. This result causes Pleiotrophy Pleiotrophy is one gene that causes many different characteristics . Future Breakthrough for Sickle Cell •Scientist are hoping to use a new medication that will dilate the blood vessels in patients. Bone marrow transplants