BCH 461 - EXAM 3 QUESTIONS AND ANSWERS

DNA to RNA is known as what? - Answer-Transcription RNA to Protein is known as what? - Answer-Translation What are the three building blocks of nucleic acids? - Answer-1. Base 2. Phosphate 3. Sugar What is the major difference between RNA and DNA in terns of structure? - Answer-The 2' Carbon, DNA has a H attached to it where RNA has a Hydroxyl (OH) attached to it. What are the RNA bases? - Answer-Guanine Adenine Cytosine Uracil What are the DNA bases? - Answer-Guanine Adenine Cytosine Thymine Why does DNA contain Thymine? - Answer-Cytosine spontaneously deaminates to form Uracil, so if DNA did not use Thymine there would be the potential for GAUU - because the Cytosine would be converted to Uracil. What makes up nucleosides? - Answer-Nucleosides are only made up of sugar and base, there is NO phosphate. What do glycosidic bonds link? - Answer-They link together nitrogenous bases and sugars to form nucleosides. What do sugars do to nucleosides? - Answer-They make nucleosides more water soluble than free bases (hydrophobic) The nucleotide backbone is ____________. - Answer-Floppy What two conformations are there around the glycosidic bond? - Answer-There is a Syn and an Anti conformation. Why does RNA prefer the C3'-endo? - Answer-RNA prefers C3'-endo because of the 2' Carb