Post on 04-Jan-2016
transcript
Proteins
Slide 2 of 19
Proteins
Polymers composed of amino acids
Protein = Polypeptide (polymer) Monomer = Amino acids
Peptide bonds
Amino acid Amine Group (NH2)
Basic Carboxylic Acid Group (COOH)
Acidic
Slide 3 of 19
Slide 4 of 19
Protein Functions
Slide 5 of 19
Slide 6 of 19
4 Levels of Protein Structure
Primary level Sequence of amino acids Polar covalent bonds link the amino acids Only level that doesn’t use hydrogen bonds
Secondary Hydrogen bonding between amino acid side groups The sequence of amino acids converts into 1 of 2 forms
α-helix β-pleated sheets
Slide 7 of 19
1’ and 2’ Levels Protein Structure
Slide 8 of 19
1’ & 2’ Animations
05_21aPrimaryStructure.swf
05_21bSecondaryStructure.swf
Slide 9 of 19
3’ & 4’ Structure
Tertiary 3D shape of a polypeptide Many types of bonds/interactions between side groups Disulfide bridges are most significant here
Quaternary 2 or more polypeptides (subunits) of a protein Not found in all proteins Same bonds/interactions as tertiary level
Slide 10 of 19
Tertiary & Quaternary Levels
Slide 11 of 19
Slide 12 of 19
3’ & 4’ Animations
05_21cTertiaryStructure.swf
05_21dQuaternaryStructure.swf
Animation-03-01.swf
Slide 13 of 19
Slide 14 of 19
Slide 15 of 19
Protein Denaturation
Slide 16 of 19
Protein Denaturation
Denaturation Protein unravels and loses its native conformation
Structure & Function Change in the protein’s structure = loss of function
Denaturation occurs: Organic solvent Any chemical that disrupts the tertiary structure Heat (excessive)
Slide 17 of 19
Chaperonins
Proteins that assist the proper folding of other proteins
Provide stable, insulated environment for polypeptide to achieve the correct conformation
Slide 18 of 19
Protein Questions
Name all of the bonds in primary protein structure?
What bonds hold together secondary structure?
What about tertiary level? Quaternary?
Which level of protein structure is NOT found in all proteins?
Slide 19 of 19
Protein Questions (Page 2)
What is the name of a protein’s monomer?
What is the name of a protein’s polymeric form?
What are the 2 functional groups on an Amino Acid?