Gene Expression Flashcards
What does gene expression involve
Transcription and translation
Transcription and translation involve three types of ribonucleic acid:
Messenger RNA
Transfer RNA
Ribosomal RNA
What is RNA
RNA is a single stranded molecule and is composed of RNA nucleotides containing ribose sugar, phosphate and one of four bases: cytosine, adenine, guanine and uracil
Transcription begins
When RNA polymerase moves along DNA unwinding the double helix and breaking the hydrogen bonds between bases.
What does RNA polymerase do
RNA polymerase synthesises a primary transcript of mRNA from RNA nucleotides by complementary base pairing. Uracil in RNA is complementary to adenine.
mRNA carries a copy……
Of the DNA code from the nucleus to the ribosome
What is each triplet of bases on the mRNA molecule called
Codon and codes for a specific amino acid
Ribosomal RNA
Ribosomal RNA and proteins form the ribosome
Function of tRNA
tRNA carries its specific amino acid to the ribosome
What is tRNA involved in
The translation of mRNA into a polypeptide at a ribosome.
Where does translation begin and end
Translation begins at a start codon and ends at a stop codon
How do anticodons bond to codons
By complementary base pairing, translating the genetic code into a sequence of amino acids.
What joins amino acids together
Peptide bonds
What is formed when tRNA leaves the ribosome
When the polypeptide is formed
