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
What is the tRNA’s job in translation during protein synthesis?
to carry specific amino acids.
What are the group of complementary base in tRNA called?
anticodons
tRNA carries ________ amino acids to the ribosome of the cell.
specific
anticodons bind the the codoms from __ —-> ___ direction.
3’ -___. 5’
what is the bond between the amino acids called?
peptide
What does a long chain of peptide bonds create?
polypeptide chain.
How does protein synthesis stop in the ribosome?
by a stop codon being added.
How does protein synthesis start during translation?
start codon
The polypeptide is produce as a ____ chain of amino acids.
single
What’s the correct shape of a protein?
the polypeptide must be folded into the correct sape.
How is the protein held together?
by hydrogen bonds along with other interactions between amino aicds.
