Tertiary Stucture Spot the Tertiary folding. Quaternary Structure Spot the Heme group (Side chains have been omitted for clarity.)
Ocean County College BIOL 161 Lectures Chemistry of Life … ...Better known as … BIOCHEMISTRY! BIOL161_03
FUNCTIONAL GROUP STRUCTURAL FORMULA EXAMPLES COMPOUNDS Hydroxyl - OH Ethanol Carbohydrates, proteins, nucleic acids, lipids Carbonyl - C = 0 Acetaldehyde Carbohydrates, nucleic acids Carboxyl OH - C = 0 Acetic Acid Proteins, lipids Amino H - N H Alanine Proteins, nucleic acids Sulfhydryl - S - H Cysteine Proteins Phosphate O - - O – P – O O Glycerol Phosphate Nucleic acids Methyl H - C – H H Alanine Proteins Primary Functional Chemical Groups (click on 'Examples' for more information)
Fred Sanger and Insulin <ul><li>Dr. Sanger is one of four people to have been awarded two Nobel Prizes and the only person to receive two prizes in Chemistry!
His discoveries in protein chemistry allowed him to sequence porcine insulin and deduce its structure.
Later, working with RNA – he was the first person to sequence an entire genome (granted a virus; but he did it by hand!). </li></ul>
Secondary Structure <ul><li>Secondary structure describes the way the chain folds. </li><ul><li>Alpha ( α )- helix </li><ul><li>Repeating spiral </li></ul><li>Beta ( β )- sheet </li><ul><li>Zig zagging elements </li></ul><li>Most proteins are a combination of both! </li></ul></ul>
α -helices can 'twist' in either direction <ul><li>Right-handed twist on the left
repeatedly wrapped into a rope, the whole forming a helix. </li></ul>
Real collagen <ul><li>Electron micrographs of collagen fibres from (a) a bird's neck and (b) a rat's tail. </li></ul>(a) (b)
Three dimensional structure <ul><li>Tertiary structure </li><ul><li>the shapes which form when the secondary spirals of the protein chain further fold up on themselves. </li></ul><li>Quarternary structure </li><ul><li>any final alterations in the protein required for biological activity </li><ul><li>Chains may bind together or other inorganic substances may be incorporated into the molecule.
Prosthetic groups <ul><li>Porphyrin Ring </li><ul><li>In both hemoglobin and myoglobin, there is an Iron (Fe) ion at the center and carries oxygen (O). </li></ul><li>A similar porphyrin ring, with magnesium (Mg) at its center is the essential part of a Chlorophyll molecule, and required for photosynthesis! </li></ul>
Protein types <ul><li>Fibrous proteins </li><ul><li>like Collagen, Silk, Keratin (hair) and Chitin (insect exoskeleton) tend to be insoluble and strong and so they have a structural role for support or protection.
What is their predominant secondary structure? </li></ul><li>Globular proteins </li><ul><li>The most common group are enzymes, which control the reactions in living cells. They tend to be soluble and, due to their globular shape include an active site. </li></ul></ul>
Lysozyme <ul><li>An enzyme found in tears and mucus which acts as a strong anti-bacterial agent because it digests bacteria cell walls.
It has 129 amino acids folded in both alpha helices and anti-parallel hairpins.