PROTEIN SYNTHESIS

Overview DNA  RNA  Protein

DNA  RNA DNA stays in the nucleus, RNA is mobile Differences between DNA and RNA Sugar: DNA = deoxyribose; RNA = ribose Number of Strands: DNA is double stranded, RNA is single-stranded Nitrogenous base: DNA contains Thymine (T), RNA contains Uracil (U) Which complements which other base??

Types of RNA Messenger RNA (mRNA) Transfer RNA (tRNA) Carries information from DNA to the rest of the cell Transfer RNA (tRNA) Codes for and transfers amino acids to ribosome Ribosomal RNA (rRNA) Components of ribosomes (~2/3)

mRNA, tRNA, and rRNA: Pictures Transfer RNA Ribosomal RNA Messenger RNA

Producing RNA: Transcription Definition: the production of RNA from DNA DNA is a template to produce complementary RNA What does this mean? “Unzipping” of DNA starts the process (similar to DNA replication*) Done by an enzyme Starts at “promoter” regions of DNA RNA is formed as a complementary strand, and then breaks off “Editing” to remove certain parts

From RNA to Protein: Some definitions Polypeptides: links of amino acids that form proteins Genetic code: the four nucleotides (A, C, G, and U) that code for proteins Codon: the three nucleotide “word” that codes for a single amino acid

From RNA to Protein: Translation Definition: Decoding of mRNA into a protein Ribosome attaches to mRNA at “start” codon tRNA (containing anti-codon) brings corresponding amino acid Ribosome attaches amino acids to chain When ribosome reaches a “stop” codon, it releases the polypeptide and the mRNA

Translation