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From Nucleotide Sequence to Amino Acid Sequence. The language of nucleic acids will be translated into the language of amino acids. What is the language of nucleic acids?. DNA molecule. Gene 1. Gene 2. Gene 3. DNA strand. Transcription. RNA. Codon. Translation. Polypeptide.
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From Nucleotide Sequence toAmino Acid Sequence • The language of nucleic acids will betranslated into the language of amino acids
What is the language of nucleic acids? DNA molecule Gene 1 Gene 2 Gene 3 DNA strand Transcription RNA Codon Translation Polypeptide Amino acid
When DNA is transcribed theresult is an RNA molecule • RNA is then translated into a sequenceof amino acids in a polypeptide • Triplets of bases • are called codons and they specify all the amino acids
The Genetic Code – our translating dictionary • The genetic code is the set of rules translating nucleotide sequence to amino acid sequence
Transcription: From DNA to RNA • In transcription • genetic information is copied from DNA to RNA • RNA molecule is transcribed from a DNA template
RNA nucleotides RNA polymerase Newly made RNA Direction of transcription Template strand of DNA (a) A close-up view of transcription
Three Phases of Transcription • The “start transcribing” signal is anucleotide sequence called a promoter • The first phase of transcription is Initiation • The second phase of transcription is Elongation • The third phase of transcription is Termination
Translation Translation: The Players • conversion from the nucleic acidlanguage to the protein language
mRNA Messenger RNA (mRNA) • message sent from the DNA in the nucleusout into the cytoplasm, to the ribosomes
tRNA Transfer RNA (tRNA) Amino acid attachment site • carriesamino acids • matches codons with anticodons Hydrogen bond RNA polynucleotide chain Anticodon Anticodon
Ribosomes Ribosomes tRNA binding sites • organelles that make proteins • made of two protein subunits A site P site Large subunit mRNA binding site A P Small subunit (a)
Translation is divided into three phases Translation: The Process • Initiation • Elongation • Termination
A fully assembled ribosome holds tRNA and mRNA for use in translation Next amino acid to be added to polypeptide Growing polypeptide tRNA mRNA
The flow of genetic information in a cell Review: DNA RNA Protein
CHAPTER 11 – DNA TECHNOLOGY • The DNA of two people of the same sex is over 99% identical • Animals, plants, and bacteria can be genetically modified to produce human proteins
BIOLOGY AND SOCIETY:HUNTING FOR GENES • DNA technology has created many advances • Genetically Modified (GM) food • DNA fingerprinting • Human Genome Project
RECOMBINANT DNA TECHNOLOGY • Recombinant DNA is combining genesfrom different sources; GM organism
From Medicine to Food • Put a gene into a bacterium and its proteinscan be produced in large quantities
Making Humulin • Humulin, 1982
DNA technology develops vaccines • a vaccine is a harmless version of a pathogen
Genetically Modified (GM) Foods • DNA technology replaces plant-breeding programs • half of American crops of soybeans and corn are GM
“Golden rice” has been genetically modifiedto contain beta-carotene; Vitamin A
“Pharm” Animals • GM animals are less common; sheep with ahuman blood protein for cystic fibrosis
Recombinant DNA Techniques • Bacteria are the workhorses • Biologists use bacterial plasmids– small, circular DNA molecules
Plasmids easily incorporate foreign DNA • they act as vectors, carriers that move genes
Cell containing geneof interest Host cell 1 DNA Recombinant DNA(host DNA plusgene of interest) 2 Gene ofinterest Cell multiplies andproduces protein 3 Genes may be insertedinto another organism Protein may be harvested OR Gene for pest resistanceinserted into plants Protein dissolves blood clotsin heart attack therapy