Lecture Notes for Oct 9, 2008

DNA ? daughter strand is exactly the same as the parental strand Comparison of DNA and RNA ? Pentose Sugar/ Deoxyribose nucleotides/ Ribose nucelotides ? Nitrogen Bases/ Thymine/ Uracil ? # of strands/ 2/ 1 ? shape/ helix/ variable ? location/ nucleus mitochondria/ nucleus cytoplasm ribosomes ? reproduction/ exact/ complementary of DNA ? forms/ one/ three- messenger ribosomal transfer Transcribed RNA ? introns- segments of RNA which do not code for a particular function ? exons- segments of RNA which carry a code to produce a particular protein or functional segment of RNA ? introns are sliced out to make a mature molecule of RNA Triplets ? AUG ? CGA ? UAG Genetic code found on M-RNA 1. codons are found sequentially on RNA only 2. the code is read from the beginning without punctuation 3. the code is redundant (degenerate) in that there is often more then one codon for each amino acid 4. there are control codons ? start codons- AUG ? stop codons- UAG, UAA, UGA 5. there may be some overlap in the code 6. the code is universal (central dogma) ? AUG- methionine ? UUC- phenylalanine ? AAG- lysine ? CAC- histadine ? UGG- trytophane ? UUC- phenylalanine ? CGU- argenine ? UAG- stop ? Anticodon- complement to a codon (tRNA) 1. gene in DNA (template strand) 2. mRNA (codons) 3. tRNA (anticodons) 4. protein (amino acids)