9.1 Transcription

Central Dogma DNARNAPROTEIN TranscriptionTranslation

Genes  DNA consists of genes  Each gene has a specific sequence (order) of nucleotides  The order of nucleotides determines what protein is made

Proteins  Monomer : amino acids  The order of nucleotides in DNA determines the order that amino acids are bonded together to make a protein  Order of amino acids determines function of protein  Different order of a.a.different protein

RNA Structure  Monomer: Nucleotides  Bases:  Adenine, guanine, cytosine, uracil  Sugar:  Ribose  Sugar-phosphate backbone  Single-stranded

RNA Types  rRNA  Ribosomal RNA  Used to make ribosomes  mRNA  Messenger RNA  Made during transcription in nucleus  tRNA  Transfer RNA  Brings new amino acids to growing protein during translation  In cytoplasm

Transcription  Location : nucleus  Goal:  Make a temporary mRNA strand complementary to one gene  Remember: complementary bases DNARNA A T C G

Transcription 1. RNA Polymerase (enzyme) unzips a part of DNA  Separates DNA strands of one gene ONLY 2. RNA polymerase  Adds complementary RNA nucleotides to one template DNA strand (strand used to make mRNA)

Transcription 3. RNA nucleotides bond together  Create a RNA sugar-phosphate backbone  mRNA strand is finished! 4. mRNA leaves nucleus, DNA rezips & stays in the nucleus

Transcription

You try it  Given the following DNA code, make the complementary mRNA strand DNA Template: T A C T T A C G A A C G G T A mRNA strand: AUGAAUGCUUGCCAU