Biology 2170 Week 3 Notes
Biology 2170 Week 3 Notes BIOL 2170 - 002
Popular in Fundamentals of Life Science: Biomolecules, Cells, and Inheritance
BIOL 2170 - 002
verified elite notetaker
Popular in Biology
This 3 page Class Notes was uploaded by Katie Veselka on Friday September 9, 2016. The Class Notes belongs to BIOL 2170 - 002 at University of Toledo taught by Robert M. Stevens in Summer 2016. Since its upload, it has received 31 views. For similar materials see Fundamentals of Life Science: Biomolecules, Cells, and Inheritance in Biology at University of Toledo.
Reviews for Biology 2170 Week 3 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/09/16
Lecture 5: Translation 09/07/2016 A) Protein a) Amino acids bind together covalently by peptide bonds to form the polypeptide chain I) Peptide bond is inflexible, no rotation possible II) Hydrolysis will break a peptide bond B) Structure of Proteins a) The primary structure of a protein is the sequence of amino acids I) The sequence determines the secondary and tertiary structure (1) How the protein is folded (2) The number of different proteins that can be made from 20 amino acids is enormous II) All proteins begin with M (Methionine) b) Secondary structure I) Localized 3d structure II) α Helix (1) Right handed coil resulting from hydrogen bonding III)β Pleated sheet (1) Two or more polypeptide chains are aligned c) Tertiary structure I) Bending and folding results in a macromolecule with specific 3d shapes II) The outer surfaces present functional groups that can interact with other molecules III)Tertiary structure is determined by interactions of R-groups (1) Covalent (2) Ionic (3) Hydrogen bond (4) Van der Waals forces d) Quaternary structure I) Results from the interaction of subunits by all types of chemical bonds e) Changes in structure I) High temp and pH changes can change the structure of the secondary and tertiary structure II) Denaturation- loss od 3d structure and thus the loss if the function of the protein f) Protein Folding I) Denatured or newly synthesized protein can sometimes bind to other molecules inappropriately (aggregate) (1) Chaperon proteins help to prevent this C) A polypeptide chain is like a sentence I) The capital letter is the amino group if the first amino acid (1) The N-terminus II) The period is the carboxyl group of the last amino acid (1) The C-terminus D) Translation a) Release factors code to stop translation b) Ribosomes I) Site of protein synthesis II) Holds mRNA and tRNA in the correct positions to allow peptide bind formation III)Big and complex IV) Made of proteins and RNAs V) Can make any type of protein VI) Catalytic activity (1) Accelerating a chemical reaction (forming the peptide bind) c) Ribosomal RNA (rRNA) catalyzes peptide bonds and provides structures d) Transfer RNA (tRNA) is an adapter between m RNA code and the amino acids used to make a polypeptide I) They carry amino acids for the process of translation II) For each amino acid, there is a specific tRNA (1) Covalent attachment between amino acid and tRNA (2) e) Codon I) A non-overlapping group of three adjacent nucleotides in the mRNA that codes for a single amino acid in a polypeptide chain II) One correct reading frame in the mRNA (1) The AUG ‘start’ codon defines the reading frame f) Anicodon is g) Aminoacyl tRNA synthetase I) Making tRNA amino acid structures h) Experiment by Benzer and others I) Chemically changed C to A when already bound to tRNA II) Resulting polypeptide had alanine in every place cysteine should be III)Protein synthesis machinery recognizes the anticodon, not the amino acid i) The genetic code specifies which amino acid corresponds to each possible codon sequence j) Start codon I) AUG – initiation code k) Stop codons I) UAA, UAG, UGG II) Stop translation and releases polypeptide l) For most amino acids there are more than one codon I) Each codon specifies only one amino acid m) Wobble I) Specificity for the base at the 3’ end of the codon is not always observed II) Allows cells to produce fewer tRNA species E) Genetic Code a) How was it deciphered I) 20 “code words” (amino acids) are written with only four ‘letter’ (Bases) II) Triplet code seemed likely (1) Could account for 4 x 4 x 4 x 4=64 F) Translation Process a) Large subunit has three tRNA binding sites b) A site I) Charged tRNA binds to the mRNA c) P site I) Chain is transferred to amino acid on the incoming tRNA d) E site I) Where the tRNA sits before being released