Transcription & Translation Flashcards
What is transcription
The synthesis of mRNA from a section of DNA
What is the role of RNA polymerase
It moves along the DNA unwinding the double helix and breaking the hydrogen bonds and adds new RNA nucleotides following RNA base pairing rules
What is left after the RNA polymerase
The primary transcript
What are introns
Regions of the transcript that are non-coding
What are exons
The coding regions
What happens during RNA splicing
Introns are cut out and exons are joined together( order of exons unchanged)
After RNA splicing what is the transcript known as
The mature transcript (code for a protein)
What is translation
The synthesis of a polypeptide from mRNA at the ribosome
Where does translation occur
The cytoplasm
First stage of translation
tRNA picks up a specific amino acid and takes it to the ribosome
2nd stage of translation
Codon and & anti codon pair up using complementary base pairing
3rd stage of translation
Peptide bond forms between adjacent amino acids
4th stage of translation
tRNA is released to pick up another amino acid
What happens after the 4th stage of translation
Amino acids joined by peptide bonds
Describe alternative RNA splicing
Different segments of mRNA may be treated as exons and introns. The same primary transcript can produce several mature transcripts
What forms a polypeptide
Amino acids are linked by peptide bonds to form a polypeptide
What do polypeptides fold to form
A 3D shape that is held together by hydrogen bonds and interactions between individual amino acids
What does a proteins shape do
Determines their function
What is a phenotype determined by
The protein produced as a result of gene expression which can be infulcened by environmental factors
State the stages in the flowchart for transcription
DNA strands separate & hydrogen bonds break ⬇️
RNA polymerase adds RNA nucleotides using complementary base pairing ⬇️
Creates primary transcript ⬇️
Splicing occurs removing introns & joining exons⬇️
Creates mature transcript
State the stages in the flowchart for translation
Mature transcript leaves the nucleus to go to ribosome⬇️
Ribosome reads mRNA in triplets known as codons⬇️
Ribosome sends signals for complemtary tRNS containing anti-codon & amino acid to pair with codon⬇️
Amino acids joined by peptide bonds & tRNA leaves to pick up another amino acid
