Protein Synthesis Flashcards
(18 cards)
Transcription:
-Occurs in nucleus
-Performed by RNA Polymerase
-DNA is the template
Translation:
-Occurs in the cytoplasm
-RNA is Template for protein
what does one triplet code make (1 codon)
1 amino acid
what are the 3 stages of transcription
- initiation
- elongation
- termination
when is mRNA processed?
before leaving the nucleous
Initiation:
RNA polymerase opens the DNA strands & begins to build RNA using DNA as a template.
Elongation:
RNA polymerase moves along and builds the RNA strand in the 5’ to 3’ direction.
Termination:
RNA polymerase hits the stopping point and falls off the DNA strand → partially completed mRNA (transcript)
what is RNA splicing
removal of introns (noncoding segments of DNA)
this happens during processing
what happens to mRNA before leaving the nucleus
it is modified: A ‘5 Guanine cap and a Poly(A) Tail are added.
They aid in allowing the mRNA to exit the nuclear membrane.
large scale DNA mutation
(long segments of DNA) translocations, duplications, and inversions
small scale DNA mutation
Point mutation
Single base change in a gene.
when can DNA mutations occur
Can happen during DNA replication/recombination. These are spontaneous.
silent mutation (point)
Little to no loss in protein structure/function
nonsense mutation (point)
Stop sequence - Early termination
Incomplete Protein
conservative missense mutation (point)
Function preserved or altered slightly - similar AA functional group
non-conservative missense mutation (point)
Protein Structure/Function hindered
what can insertions or deletions cause
a frameshift mutation unless they are in multiples of 3.
