Protein Synthesis. From DNA to RNA to Protein. Biol 219 Fall 2016 Lec 6 Dr Scott. BioFlix: Protein Synthesis. Genes

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1 Biol 9 Fall 06 Lec 6 Dr Scott From to to Protein Protein Synthesis Gene onstitutive proteins (essential to ongoing cell functions) are made at all times Regulated genes are turned on and off as needed (by regulatory proteins) Trans cription Synthesis of by copying information in Trans lation Synthesis of protein off the information in 06 Pearson Education, Inc. Genes A gene is a specific segment of that contains information needed to make a functional piece of, which in turn is necessary for producing a specific protein. How do we make a protein from the information within a gene? BioFlix: Protein Synthesis 06 Pearson Education, Inc. Fig..8 opyright 00 Pearson Education, Inc.

2 Biol 9 Fall 06 Lec 6 Dr Scott Transcription ast of characters: Nucleotides polymerase Trans cription factors Mg + or Mn + ATP Transcription factors guide the polymerase into place on the promoter of the gene. Fig..9 opyright 00 Pearson Education, Inc. Fig..9 opyright 00 Pearson Education, Inc. Fig..9 opyright 00 Pearson Education, Inc. polymerase binds to. The sect ion of t hat cont ains the gene unwinds. bas es bas es bind t o, creating a single of. Tem plat e Sit e of nucleot ide assem bly Lengthening transcript and the polymerase det ach f r om, and t he goes to the cytosol after pr ocessing. released Fig..9 opyright 00 Pearson Education, Inc. Figure.9 Transcription Leaves nucleus 06 Pearson Education, Inc. af t er pr ocessing

3 Biol 9 Fall 06 Lec 6 Dr Scott Synthesis polymerase Promoter Trans cription factors Alternative splicing Several possible proteins from a single gene 06 Pearson Education, Inc. Fig..0 opyright 00 Pearson Education, Inc. Translation When enters the cytoplasm, it must associate with the protein synthesis machinery ast of characters: ribosomes amino acids Translation of Trans lation components, rs, and s Ribosomes and amino acids 06 Pearson Education, Inc. Transfer attachment : Binds to a s pecific amino acid. attaches to a (phenylalanine) = yto si n e : Binds to codon on, following complementary base-pairing rules. Antic odon

4 Biol 9 Fall 06 Lec 6 Dr Scott attach es to a Fig..7 opyright 00 Pearson Education, Inc. = yto si n e attaches to a and small ribosomal ribosome and initiator fits into. A attaches to a and small ribosomal ribosome and initiator fits into. A A A G odons of incoming pairs with ne xt codon at A. = yto si n e = yto si n e attaches to a and small ribosomal ribosome and initiator fits into. A A A G odons of incoming pairs with ne xt codon at A. A A G AG Dehydration synthesis on at amino acid at A. = yto si n e

5 Biol 9 Fall 06 Lec 6 Dr Scott attaches to a and small ribosomal ribosome and initiator fits into. A A A G odons of incoming pairs with ne xt codon at A. A A G AG attaches to a and small ribosomal ribosome and initiator fits into. A A A G odons of incoming pairs with ne xt codon at A. A A G AG Ne w peptide bond on at Ne w peptide bond on at amino acid at A. amino acid at A. A G G A G G = yto si n e at leave s ribosome, ribosome shifts by one codon; previously at is now at th e. mo ve me n t 6 Stop codon Protein synthesis stops when the ribosome reaches stop codon on. = yto si n e at leave s ribosome, ribosome shifts by one codon; previously at is now at th e. Growing protein Summary of movement of ribosome along mo ve me n t omplete protein opyright 00 Pearson Education, Inc. opyright 00 Pearson Education, Inc. Post-Translational Modification Protein folding ross-linkage (disulfide bonds) leavage (if required for activation) Addition of other molecules or groups Assembly into polymeric (many part) proteins (quarternary structure, e.g., hemoglobin) opyright 00 Pearson Education, Inc.