Ch 7: RNA and the Genetic Code Flashcards
Central Dogma
DNA -> RNA -> proteins
degenerate code allows
multiple codons to encode for the same amino acid
Initiation (start) codon
AUG
Termination (stop) codon
UGA, UAA, UAG
redundancy and wobble (third base codon) allows
mutations to occur without effects in the protein
point mutations can cause
silent, nonsense (truncation), missense
silent mutations
with no effect on protein synthesis
nonsense (truncation) mutations
produce a premature stop codon
missense mutations
produce a codon that codes for a different amino acid
frameshift mutations
result from nucleotide addition or deletion, and change the reading frame of subsequent codons
RNA is structurally similar to DNA except
substitution of a ribose sugar for deoxyribose
substitution of uracil for thymine
single-stranded instead of double-stranded
3 types of RNA with separate jobs during transcription
messenger, transfer, and ribosomal
messenger RNA (mRNA)
carries the message from DNA in the nucleus via transcription of the gene; travels into the cytoplasm to be translated
transfer RNA (tRNA)
brings in amino acids, recognizes the codon on the mRNA using its anticodon
Ribosomal RNA (rRNA)
makes up the ribosome; enzymatically active