Midterms 4

• Protein Synthesis

  The process of making proteins
• Protein Synthesis

  • Has two major steps: Transcription and Translation
• Transcription


  Transcribing DNA into a message (mRNA)
• Transcription

  1. DNA is in the nucleus

  2. RNA polymerase connects complementary RNA bases to DNA

  3. Forms single-stranded mRNA
• mRNA


  Messenger RNA, carries the message from DNA to the cytoplasm
• Translation

  1. mRNA attaches to ribosome in cytoplasm

  2. Ribosomal RNA (rRNA) makes the proteins
• tRNA

  Transfer RNA, carries amino acids to the ribosome
• Translation

  1. tRNA reads mRNA codons

  2. tRNA anticodon binds to complementary mRNA codon

  3. Amino acids are bonded by peptide bonds
• Codon


  Sequence of 3 mRNA bases that codes for a specific amino acid
• Start Codon

  AUG codes for methionine, typically the first amino acid
• Stop Codon


  UAA, UAG, UGA signal the end of protein synthesis
• The result of translation is amino acids built based on the mRNA coding, which is complementary to the DNA