Chapter 17 (only trouble spots) Flashcards
Which of the following is the most probably advantage for the organism of such sigma swichting?
Might allow the polymerase to recognize different promoters under certain environmental conditions
Function of poly-A
Codes for a sequence in eukaryotic transcription that signals enzymatic cleavage
What type of RNA polymerase is involved in transcription for a globin protein?
RNA polymerase II
Why is TATA sequence only several nucleotides away from the start site of transcription?
Number of hydrogen bonds between A and T in DNA
Alternate RNA splicing…
Can allow for the production of proteins of DIFFERENT SIZES from a single mRNA
Exonucleases
Will digest mRNA if it is not protected by the 5’ end
Where do spliceosomes bind?
To the end of an intron
Usful feature of introns
Introns allow exon shuffling
Function of GTP in translation
Energizes the formation of the initiation complex, using intitation factors
First event to take place in translation in eukaryotes
Small subunit of the ribosome recognizes and attatches to the 5’ cap of mRNA
Function of a signal peptide
Translocate polypetides across the ER membrane
What must occur when a newly made polypetide wants to leave the cell
Go through the ER
Then to the Golgi
Point Mutation
Substitutes an amino acid in the active site
Frameshit mutation could result from..
insertion or deletion of a base
Cystic fibrosis mutation
Polypeptide missing an amino acid
Most likely to cause a phenotypic change
Single nucleotide deletion in an exon coding for an active site
6 cleary defined domains equals
8 exons
Gene
a DNA sequence that is expressed to form a functional product either RNA or polypeptide
Transciption in Domain Archaea
Roughly simultaneous with translation
Domain archaea has…
numerous transcription factors!
20,000 protein-coding regions implies,
there are also genes for RNAs other than mRNA
Defective enzyme A
leads to an acculumation of A and no production of B and C
What direction does RNA polymerase move?
3’ to 5’ along the template strand
Anti-codons move in..
opposite direction
3’ to 5’
