6.3: Transcription and RNA Processing Flashcards
What is transcription?
The process in which an enzyme directs the formation of the RNA molecule.
What is the central dogma?
DNA is transcribed into RNA and then folded into proteins. It is not reversible.
What is the function of mRNA?
The transcribed copy of a particular gene (messenger as needs to leave nucleus and into the cytoplasm).
What is the function of tRNA?
Transfer RNA is used by ribosomes in order to create the correct polypeptide sequence as it uses anticodons to correctly pair off.
What is the function of rRNA?
Ribosomal RNA. Help with protein assembly.
How does the mRNA, tRNA, and rRNA all interact?
mRNA goes to rRNA. At the rRNA site, there are tRNA that use anti codons to align with the mRNA so that the correct amino acids are strung together.
How does the DNA sequence determine the RNA sequence?
The DNA sequence of the noncoding strand will match the new RNA strand.
What is the function of RNA polymerase?
To synthesize mRNA in the 5’to 3’ direction.
Which strand is the template strand?
The one that the RNA uses to build its RNA.
What are the other names of the template strand?
noncoding strand, minus strand, or antisense strand.
Which direction does transcription take place (which direction is the RNA synthesized)? Which direction is the template strand read?
It is synthesized in the 5’to 3’but it is read in the 3’to 5´.
Identify three post-transcriptional modifications that alter the pre-mRNA prior to its release from the nucleus.
The introns are removed by RNA splicing, adding the poly A tail to the 3’hydroxyl end and adding the GTP cap to the 5’phosphate end.
What is the function of the poly-A tail?
The poly A tail attached to the 3´ hydroxyl end. This increases stability and helps the mRNA to leave the nucleus and into the cytosol to begin translation.
What is the function of the GTP cap?
The GTP attaches to the 5’end. It is modified Guanine that protects the transcript and helps the ribosome to be able to attach to the mRNA.
What is the function of RNA splicing?
Alternative splicing means that it takes out certain introns one time and different ones the other time meaning that multiple proteins can be made from the same code.
