Aca Molecular Genetics and Biotechnology Main Idea DNA codes for RNA, which guides protein synthesis From Genes to Genetic expression (The central dogma of molecular biology) DNA->RNA->amino acid->protein-> genetic expression Protein Synthesis Amoeba Sister Protein Synthesis http://www.youtube.com/watch?v=h5mJbP23Buo Answer the following questions in your notes as you view the video Video Questions 1. DNA codes for traits (Proteins) 2. What does Protein Synthesis make? Proteins 3. Yes or No: Is all the DNA turn on all the time? 4. DNA is located in the Nucleus 5. What are the 2 step in Protein Synthesis? Transcription Translation 6. How many letters are read at a time? 3 5 Roles of RNA and DNA DNA is the MASTER PLAN RNA is the BLUEPRINT of the Master Plan DNA vs RNA DNA Sugar-Deoxyribose Double Stranded Nitrogen Bases: Adenine, Thymine, Gaunine, Cytosine, Difference: Thymine G,C,A,T RNA Sugar Ribose Single Stranded Nitrogen Bases: Adenine, Uracil, Guanine, Cytosine Difference: Uracil G,C,A,U RNA & Protein Synthesis DNA remains in the nucleus, but in order for it to get its instructions translated into proteins, it must send its message to the ribosomes where proteins are made. There a 3 types of RNA involved in this process mRNA: tRNA: rRNA Carries genetic information from DNA in the nucleus to direct protein synthesis in the cytoplasm. (codon) mRNA Carries specific amino acids to the ribosomes. (Anti-codon) tRNA molecular component of a ribosomes. (the site of protein synthesis) rRNA Moving the information from DNA to Proteins 2 Main Steps in Protein Synthesis 1. Transcription: Takes place in the nucleus, mRNA reads the DNA strand, then moves to the cytoplasm for translation. 2. Translation: Take place in the cytoplasm, tRNA carries amino acids to the mRNA to the site of a ribosome (rRNA) In RNA Adenine pairs with Uracil Guanine pairs with Cytosine (A-U) (G-C) Replicatio n Cell DN A transcription mRNA translation Protein Synthesis In Cytoplasm on Ribsomes Nucleus Circle a Codon and put a square around and Anti-Codon What biomolecule does the growing amino acid chain make? _____________ What process is shown in X? What process is shown in Y? What process is shown in Z? How does mRNA code for proteins? DNA TACGCACATTTACGTACGCGG Ribosome mRNA AUGCGUGUAAAUGCAUGCGCC ? MetArgValAsnAlaCysAla Protein aa aa aa aa aa aa aa How can you code for 20 amino acids with only 4 DNA bases (A,U,G,C)? aa mRNA Codes for Proteins in Triplets DNA TACGCACATTTACGTACGCGG Codon mRNA Protein Ribosome AUGCGUGUAAAUGCAUGCGCC MetArgValAsnAlaCysAla Codon = block of 3 mRNA bases How are the Codons Matched to Amino Acids? DNA TACGCACATTTACGTACGCGG mRNA AUGCGUGUAAAUGCAUGCGCC Codon UAC tRNA Amino Acid Met GCA Arg CAU Anti-codon Val Anti-codon = block of 3 tRNA bases mRNA to protein = Translation The working instructions mRNA The reader ribosome The transporter transfer RNA (tRNA) Ribosome mRNA A C C A U G U C G A U C A G U A G C A U G G C A U G G tRNA aa aa aa U A C tRNA aa A G tRNA aa C U A G tRNA aa Remember we use the Codon Chart only for mRNA DNA CCT CTT TAC ACA CGG AGG GTA CGC TAT TCT ATG ATT ACA CGG TTG CGA TCC ATA ATC mRNA protein Protein Synthesis Mark through the tRNA. Only use mRNA for the correct Amino Acid aa Cytoplasm aa Protein aa Nucleus aa aa Transcription Translation aa aa aa aa aa aa Trait Protein Transcription Translation Protein Synthesis Worksheet: Mutation Video http://www.youtube.com/watch?v=GieZ3pk9YVo Mutations: Mutation can be harmful, helpful or neutral in their effect. Mutations create genetic variation Mutations are ANY changes in the genetic material. A mutation that occurs in the gametes will most likely transferred to the offspring Types of Gene Mutations Include: Point Mutations: Change of a single nucleotide. Include: 1. Substitution: Change in the nucleotide 2. Frameshift: insertion or deletion of a single nucleotide Gene Mutations: Substitution Gene mutations result from changes in a single gene. A change in one base; aka point mutation. In substitution, one base replaces another. Substitution Gene Mutations: (Frameshift) Insertion/Deletion In an insertion, an extra base is inserted into the base sequence. The loss of a single letter shows the effect of a deletion. Deletion Insertion Shifts right or left in reading frame = Frameshift mutation Mutation Type Normal Missense (substitution) Nonsense (substitution) Deletion (causing frameshift) Insertion (causing frameshift) Duplication Analogy Sentence Example of Associated Disease THE BIG FAT CAT ATE THE WET RAT THE BIZ FAT CAT ATE THE WET RAT Achondroplasia: improper development of cartilage on the ends of bones of arms and legs resulting in a form of dwarfism THE BIG RAT Muscular Dystrophy: progressive muscle disorder characterized by the progressive weakening of many muscles in the body THB IGF ATC ATA TET HEW ETR AT Cystic fibrosis: characterized by abnormally thick mucus in the lungs, intestines, and pancreas THE BIG ZFA TCA TAT ETH EWE TRA Crohn’s disease: chronic inflammation of the intestinal tract, producing frequent diarrhea, abdominal pain, nausea, fever, and weight loss THE BIG FAT FAT CAT ATE THE WET RAT Charcot-Marie-Tooth disease (type 1A): damage to peripheral nerves leading to weakness and atrophy of muscles in hands and lower legs. Expanding mutation (tandem repeats) Generation 1 THE BIG FAT CAT ATE THE WET RAT Generation 2 THE BIG FAT CAT CAT CAT ATE THE WET RAT Generation 3 THE BIG FAT CAT CAT CAT CAT CAT CAT ATE THE WET RAT Huntington’s disease: a progressive disease in which brain cells waste away, producing uncontrolled movements, emotional disturbances, and mental deterioration Chromosome Mutations Five types exist: Deletion: removes a chromosome segment Inversion: reverses a segment within a chromosome Translocation: moves a segment from one chromosome to another, non-homologous one Duplication: repeats a segment Non-disjunction: chromosomes fails to separate properly during meiosis Chromosome mutations creates genetic variation Mutation Worksheet QUIZ TIME 1. The diagram shows the normal sequence of genes in a particular chromosome. Which chromosomes could have resulted from a deletion that occurred in this chromosome? Applied Genetics: is the manipulation; of the hereditary characteristics of an organism to improve or create specific traits in offspring. Selective breeding: directed breeding to produce plant and animal with desirable traits. Ex: breeding plants to produce larger fruits/vegetable Gel Electrophoresis 1. DNA is cut into smaller pieces using restriction enzymes 2. An electrical current is applied 3. DNA is separated by size. Shorter fragments move farther down the get than longer fragments Used in: DNA fingerprinting DNA fingerprinting • Best way to determine if two people are genetically related • Used in genetic counseling, parental testing, crime scenes, classification of new species of organisms. • Can you tell… Organism X is most closely related to which sample? Gel Electrophoresis (example) Look at the example of DNA taken at the crime scene (Column 1). Which suspect committed the crime? Suspect 1 Suspect 2 Suspect 3 Chromosome Painting • Scientists use chromosome painting to make the locations of genes on human chromosomes with fluorescent tags. It is also possible to apply this technique to compare genomes of different species Nucleus What have we learned: From Gene to Protein:aa Review aa Transcription DNA aa Translation mRNA aa Protein aa aa aa A C C A UGU C G A UC A GUA GC A U GGC A Cytoplasm tRNA aa Ribosome Trait Mutations Single Nucleotide Mutations Chromosome Mutations Non-disjunction Biotechnology: is the use of genetic engineering to find solutions to problems.