BIOLOGY 111 1st Edition Lecture 6 Outline of Last Lecture I Functional Groups II Four major Biomolecules III Dehydration and Hydrolysis Reactions IV Carbohydrates V Lipids VI Proteins Outline of Current Lecture I Polypeptides II Proteins structure A Primary B Secondary C Tertiary D Quaternary III Nucleic Acids A Nucleotides B Polynucleotides C Chargaff s rule Current Lecture Polypeptide peptide bonds connect amino acids by dehydration lose one water molecule N terminus C terminus Proteins are always in 3D spherical globular round in shape or fibrous ribbon like and found mostly in muscles ex collagen part of our body s framework bones 1 protein structure more complex A primary single chain of amino acids provides structure coding for how a protein will be made B secondary interactions backbone of polypeptides causing coils or folding repeated structure a alpha helix looks like a ribbon 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 b beta pleated sheet looks like jagged sheets need H with a partial charge to make bonds and hold secondary structure alpha and or beta together C tertiary most common gives 3D shape and contains a combination of alpha helix and beta sheet a R group is very important because they form a variety of bonds which stabilize the tertiary structure 1 hydrogen bonds 2 hydrophobic and Van der Waals interactions asymmetrical charges 3 Disulfide Bridge occurs when have sulfur 4 Ionic bonds D quaternary only formed when there are 2 or more polypeptides ex hemoglobin 4 polypeptides and collagen changing any part of any structure will result in a change throughout the stages after ex if you change the primary structure expect a change in the secondary tertiary and quaternary ex would be Red blood cell shape can be changed by replacing only one glu with valine and will result in sickled red blood cell this causes problems like anemia because they don t have enough oxygen flowing in their blood may always affect secondary or tertiary but not necessarily always affect quaternary unfolded or denatured proteins lose their normal properties BUT some proteins can successfully refold and renature salt concentration water content temperature affect the function of protein denatured proteins do not function like a normal protein chaperonins when protein folding takes a structure it is done naturally and no outside help it protects the protein while it is being folded from improper interactions like going into a beauty parlor and coming out looking like a new person it is a protein itself so made up of amino acids Nucleic Acids Genes are made of DNA a nucleic acid the amino acid sequence of a polypeptide is programmed DNA one type and RNA variety of types are polynucleotides which store and process info Nucleotides nucleic acid polynucleotide monomer polynucleotide held together by phosphate bonds Pyrimidines C T U Purines A G Phosphate bonds phosphodiester bonds hold nucleotides together between the sugars Chargaff s rule A T and G C complementary base pairing by 5 end and 3 end ex hydrogen bonding between nitrogenous bases in RNA A U and G C Test 1 ends here 40 questions 41 including bonus mostly multiple choice