RNA (Ch 13.1)

The Role of RNA General Basics Now that we know what DNA is, the question still remained as to how it worked? RNA RiboNucleic Acid  uses ribose sugar instead of deoxyribose Consists of ONE long chain of nucleotides General Basics DNA consists of how the protein should be built  DNA needs to be copied to RNA  RNA contains the code for the proteins

RNA vs. DNA DNA RNA Main Components deoxyribose, phosphates, nitrogenous bases ribose, phosphates, nitrogenous bases Number of Strands Double helix (2 strands) Single stranded Nitrogenous bases Adenine, cytosine, guanine, thymine Adenine, cytosine, guanine, uracil Task Master plan Blueprints DNA is housed safely in the nucleus. If you took your master plan out of the “safe zone” and something happened to it, could remember every fact or detail to put it back together the exact same way? RNA provides a blueprint or a copied version of the master copy. This allows for the instructions to leave the “safe zone.” If it is damaged or destroyed, the plans can be recopied.

DNA vs. RNA

Functions of RNA One job: Protein Synthesis RNA controls the production of proteins, which are made of amino acids Amino Acids: the building blocks of protein (20 amino acids) Three Types of RNA Messenger RNA (mRNA): carrying the copies (blueprints) of DNA to other parts of the cell Ribosomal RNA (rRNA): proteins are assembled on ribosomes – small organelles composed of TWO subunits Transfer RNA (tRNA): transfers the amino acids to the ribosomes as specific by the coded message

Types of RNA

RNA Synthesis Eukaryotic vs. Prokaryotic DNA DNA  RNA  Protein Transcription Translation Transcription: segments of DNA serve as templates to produce complementary RNA molecules transcribing DNA code into RNA to travel in the cell most of the work occurs here Eukaryotic vs. Prokaryotic DNA Eukaryotic = nucleus Prokaryotic = cytoplasm RNA Polymerase Binds to DNA and separates DNA strands Assembles nucleotides into a complementary strand of RNA This makes it possible for a single gene to make hundreds of RNA molecules

RNA Synthesis

RNA Synthesis (cont.) Promoters: regions of DNA that have specific base sequences These allow for RNA polymerase to know where to bind to make the complementary RNA strand Similar signals tell when to stop transcription after the RNA strand is made RNA Editing Review the mRNA molecule before it is ready to be read Introns: pieces that are cut out and discarded Exons: remaining pieces that are spliced back together