Transcription And Translation Flashcards
Codon
Three nucleotides on mRNA molecules that code for specific amino acid in the protein sequence; stop codon is a a codon that codes for the signal that terminates polypeptide chain growth
What is a gene
A unit of heredity, transcription unit - a length of DNA on a chromosome that contains the code for a protein (or RNA) as well as sequences necessary for its expression, such as a promotor and terminator sequences and introns
What is the genetic code
The universal conversion table from DNA information into the amino acid information - how nucleotides are set out
What is mature mRNA
The end product of transcription - after capping, polyadenylation and splicing has occurred)
What is ORF (open reading frame)
The area of a gene that holds the code for all the amino acid residues of the gene product (the protein)
What is a Promotor
The area of the gene upstream of the ORF which regulates transcription, and therefor gene expression; these include sequences for binding of transcription factos and RNA polymerase and many other regulatory factors (activators and repressors)
What is a ribosome
A two unit particle composed of many proteins and ribosomal RNAs that is the site of protein synthesis
What are the types of RNA
mRNA - messenger RNA
tRNA - transferral RNA
rRNA - ribosomal RNA
What is the difference between Transcription and Translation
Transcription - the process by which the DNA code is copied into an RNA message
Translation - the process by which RNA message is translated into an amino acid (protein)
Transcription
- initiation
- termination
Start of mRNA production dependent on RNA polymerase binding
End of mRNA production dependent on sequence
Translation
- initiation
- termination
Start of protein production eg at the AUG codon
End of protein production eg at a stop codon (UAA, UAG, UGA)
Define anticodon
Three nucleotides on tRNA molecules that are complimentary to a codon on the mRNA template
What are the stages of transcription
Initiation
Elongation
Termination
Also, post transcriptional processes include
Capping
Tailing
Splicing
