Gene expression Flashcards
What are RNA nucleotides composed of
Ribose sugar, phosphate and a base
Differences of RNA nucleotide to DNA nucleotides
RNA: single stranded, has the base uracil, ribose sugar
DNA: double stranded, has base thymine and deoxyribose sugar.
Role of mRNA
carries a complementary copy of the DNA code from the nucleus to the ribosome.
Where is mRNA transcribed
Nucleus
Where is mRNA translated
Translated into proteins in the ribosome
What is the triplet of bases called on an mRNA molecule
Codon
What does a codon code for
A specific Amino acid
Why does a tRNA molecule fold
Due to complementary base pairing.
Role of tRNA molecule
Carries a specific amino acid to the ribosome
What is the exposed triplet of bases called on a tRNA molecule
Anticodon complementary to mRNA molecule
What forms the ribosome
rRNA and proteins
Role of RNA polymerase in transcription
Separates the DNA strands by breaking hydrogen bonds between the bases.
Adds completely RNA nucleotides to produce a primary transcript.
How is the mature mRNA transcript formed
RNA splicing
What happens in RNA splicing
Introns (non coding regions) removed
Exons (coding regions) joined together
Where does translation begin
At a start codon
Where does translation end
Stop codon
How is the genetic code translated into a sequence of amino acids
Anticodons bond to codons by complementary base pairing.
What joins amino acids together
Peptide bond
What happens to tRNA as polypeptide formed
Leaves the ribosome.
How can different proteins be expressed from one gene
Alternative RNA splicing where different Exons are retained to form the mature mRNA transcript.
What is the 3D shape of protein held together by
Hydrogen bonds
What determines proteins function
Their shape
