Gene action: protein synthesis

Gene action: protein synthesis

1. Proteins produced by synthesis determine physical and chemical characteristics of cells and organisims

   • DNA in genes provides instructions for making proteins
     • TO SYNTh PROTEINS: Info from DNA copied to produce RNA.
       • (TRANSCRIPTION) RNA attaches to a ribosome & translated to crrspndng sqnc of amino acids and form new protein molecule.
         • Info stored in DNA in 4 types of NUCLEOTIDES (repeating units of nucleic acids)
           • Each sqnc of 3 DNA ncltds is copied to RNA ncltds (BASE TRIPLET)
           • Each squnc of 3 RNA ncltds (CODON)
           • PROMOTER - segment of DNA where RNA polymerase attaches to it is this special sequence of nucleotides
         • Transcription catalyzed by enzyme RNA called POLYMERASE, which needs directions on where to start and stop transcribing
         • Ends at a nucleotide sequence on DNA called a TERMINATOR, which tells the RNA polymerase to detach from transcribed RNA molecule and DNA. WHen synthesized, mRNA, rRna and tRNA leave nucleus thru nclr pore. In cytoplasm, ready for translation.
         • During transcription, nucleotides pair in a complimentary way (If the DNA base is cytosine, the complimentary nitrogenous base guanine will go to the new RNA strand).
           • MESSENGER RNA - directs synthesis of a protein
           • RIBOSOMAL RNA - joins with ribosomal proteins to make ribosomes
           • TRANSFER RNA - grabs amino acid and holds in place on a ribosome until it becomes a protein during translation. Bind to only 1 amino acid (20)