15.1 Flashcards
Evaluate the evidence for the one-gene/one-polypeptide hypothesis.
One gene encodes for the structure of one enzyme and an enzyme contain polypeptide subunits
Define gene expression and identify the central dogma of molecular biology.
o Gene expression- process by which DNA directs protein synthesis
o Central dogma- describes the information flow in cells as DNA –> RNA –> Protein
Distinguish between transcription and translation.
o Transcription- the synthesis of RNA using information in DNA
o Translation- the synthesis of a polypeptide using information in the mRNA
List the types of RNA molecules that are synthesized from a DNA template by transcription.
o Adenine, Uracil instead of Thymine, Guanine and Cytosine
o mRNA vs. rRNA vs. tRNA
Define codon and identify the relationship between codons and amino acids.
Set of 3 nucleotides in the mRNA sequence (ex:AUG)
Identify the start codon and the stop codons.
o Start: AUG
o Stop: UAA, UGA, UAG
Explain what it means for the genetic code to be degenerate.
Some amino acids are specified by more than 1 codon
Explain how wobble pairing allows for fewer tRNAs to accommodate all codons.
o allows the cell to decode 61 codons with fewer than 61 tRNAs
o The third base in a codon does not need to pair perfectly with the anticodon
Define reading frames.
o one of three possible ways of reading a nucleotide sequence
o Ex: CUC AGC or C UCA GC or CU CAG C
Describe what it means for the genetic code to be universal.
Even simple bacteria share the same genetic code as the most complex animals
