flow of genetic info
what is the process that DNA into RNA?
transcription
what enzyme synthesizes RNA?
RNA polymerase
what is added to the 5' end of mRNA?
which ribosomal site recieves the next tRNA?
A site
how is mRNA read?
5' to 3'
this process converts mRNA into protein
translation
what DNA sequence does RNA polymerase bind?
the promoter
what is removed during splicing?
introns
what molecule carries amino acids to the ribosome
tRNA
how many nucleotides make a codon?
3 nucleotides
what molecule directly determines amino acid order?
what is mRNA?
what is the role of transcription factors?
thy help RNA polymerase bind to DNA and initiate transcription
what are the 3 major RNA processing events
-addition of the 5' cap
-addition of the poly-A tail
-RNA splicing
describe what happens during translocation
the ribosome moves on condon down the mRNA, shifting tRNSA from A to P and P to E
translate AUG GGU UAA
methionine, glycine, stop
why are proteins considered the link between genotypes and phenotypes?
genes direct protein synthesis and proteins produce observable traits
explain the difference between the template and coding strand
the template strand is used to synthesize RNA. the coding strand has the same sequence as the RNA except T is replaced with U
why do 5' caps and poly-A rails increase mRNA survival?
they protect mRNA from degradation and help export and translation
a ribosone reaches to a stop codon. why cant a tRNA enter and what would enter instead?
No tRNA matches stop codons. A release factor enters A site instead
if a student starts reading one nucleotide late, what would happen to the protein sequence
the reading frame changes which then produces different codons and a different protein which is a frameshift
a mutation changes DNA but the protein stays the same. explain how information flow prevented a phenotype change
the mutation may have been silent so the amino acid sequence didnt change and the protein function remained the same
a scientist mutates a TATA box. predict how transcription would be affected and why?
Transcription would most likely decrease or fail because transcription factors may not bind properly, preventing formation of the initiation complex
how can alternative splicing allow one gene to produce multiple proteins?
different combinations of exons can be included, different mature mRNAs and different protiens
a ribosome is translating an mRNA. a tRNA carrying the growing polypeptide is located in the P site and a charged tRNA enters the A site.
WHAT ARE THE NEXT 3 STEPS?
-codon recognition
-peptide bond formation
-translocation
why is it important that mRNA is read in groups of 3 nuecleotides whien usin a codon chart?
because each codon specifies one amino acid. Reading the sequence incorrectly would create different codons and therefore a different amino acid sequence