Ch 13 RNA and Protein Synthesis

Review Describe the three main difference between RNA and DNAExplain List the three main types of RNA and explain what they doInfer Why is it important for a single genes to be able to produce hundreds or thousands of RNA moleculesCh 13 RNA and Protein Synthesis13.1 RNA

RNANucleic acid that consists of a long chain of nucleotidesCopied from DNA.Differences Between RNA and DNASugar is ribose instead of deoxyriboseRNA is generally single-stranded and not double-strandedRNA contains uracil (U) in place of thymine (T).Comparing RNA and DNARoles of DNA and RNA are similar to the master plans and blueprints used by buildersMaster plan has all the information needed to construct a building.

Never bring a valuable master plan to the building site, where it might be damaged or lostInstead they bring inexpensive copies or blueprints.Functions of RNADisposable copy of a segment of DNAProtein synthesis.

3 Types of RNAMessenger or mRNARibosomal or rRNATransfer or tRNA.Messenger RNA

Carry copies of DNA instructions.Ribosomal RNA

Make up ribosomes.

Transfer RNA

Transfers each amino acid to the ribosome according to mRNA.TranscriptionSegments of DNA serve as templates to produce complementary RNA moleculesMakes a copyOccurs in nucleus of eukaryotes.RNA polymerase

Enzyme similar to DNA polymeraseBinds to DNA and separate strandsUses one strand of DNA as a template and makes a complementary RNA strand.Promoters

Regions of DNA that have specific base sequencesShows RNA polymerase where to bind and startSimilar signal shows where to stop. RNA EditingExonThe part of the DNA that codes for the protein that is to be madeIntronThe part of the DNA that does NOT code for the protein that is to be made.Why Have IntronsGenes and Protein instructions may overlap in DNAInstructions for one protein may cut out one set of introns, but different introns may be cut out for a different proteinDont have a complete answerNeapolitan ice cream.ChocolateExonVanillaIntronStrawberryIntron.