U1KA3 Flashcards
what is gene expression
term given to protein synethsis
what is RNA used for
to copy the genetic code and synthesise proteins from amino acids.
Structure of RNA
single stranded, ribose sugar, phosphate and bases adenine w uracil instead of thymine, cytosine w guanine.
what are the 3 types of RNA
mRNA, tRNA, rRNA
What is the first stage of protein synthesis called?
transcription.
___ polymerase unwinds the double helix, breaking the _____________ in protein synthesis, then adds complementary _______ nucleotides in a single strand to create the _________
RNA, hydrogen bond, RNA, primary transcript.
What does thymine replace w in RNA?
Uracil.
what are the coding areas called in the primary transcript?
exons
what are the non-coding areas called in the pimrary transcript
introns
the _____ are cut out of the primary transcript using enzymes
introns
what does it create once introns are cut out?
a short mature mRNA transcript
what is alternative splicing
certain genes producing more than one protein, because different enzymes can cut different introns. This results in a different mature mRNA code, therefore a different protein.
What is the second stage of protein synthesis called?
translation.
Where does translation occur?
the ribosome
What are the 3 base group in an mRNA called?
codons
