Chapter 17 Flashcards
(17 cards)
What does this describe?
- A cap consisting of a modified guanine nucleotide is added to the 5’ end of the pre-mRNA.
- Noncoding sequences called introns are spliced out by molecular complexes called spliceosomes.
- a poly-A tail (50-250 adenine nucleotides) is added to the 3’ end of the pre-mRNA.
The processing that takes place before a mature mRNA exits the nucleus
For any given gene, what ultimately determines which DNA strand serves as a template strand?
The base sequence of the gene’s promoter
What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?
Transcription
What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
Translation
What name is given to the process in which pre-mRNA is edited into mRNA?
RNA processing
Polypeptides are assembled from ___?
Amino acids
RNA processing converts the RNA transcript into ___.
mRNA
A codon of ___ bases and specifies which ___ will be inserted into the polypeptide chain.
Three…amino acid
The direction of synthesis of an RNA transcript is ___.
5’ —> 3’
Where does RNA polymerase begin transcribing a gene into mRNA?
It starts after a certain nucleotide sequence called a promoter.
What is the function of RNA polymerase?
It unwinds the double helix and adds nucleotides to a growing strand of RNA.
During RNA processing a(n) ___ is added to the 5’ end of the RNA.
Modified guanine nucleotide
During RNA processing a(n) ___ is added to the 3’ end of the RNA.
A long string of adenine nucleotides
Spliceosomes are composed of ___.
snRNPs and other proteins
The RNA segments joined to one another by spliceosomes are ___.
Exons
Translation occurs in the ___.
Cytoplasm
After an RNA molecules transcribed from a eukaryotic gene, what are removed and what are spliced together to produce an mRNA molecule witha continuous coding sequence?
Introns…exons
