AQA Unit 4 (3.4.2) DNA and protein synthesis Flashcards
What is the genome?
The complete set of genes in a cell.
What is the proteome?
The full range of proteins that a cell is able to produce.
What are the two types of RNA involved in protein synthesis?
Messenger RNA (mRNA) and transfer RNA (tRNA).
What is transcription?
The production of mRNA from DNA.
What role does RNA polymerase play in transcription?
Joins mRNA nucleotides by phosphodiester bonds.
In prokaryotes, transcription results directly in the production of _______.
mRNA.
In eukaryotes, transcription results in the production of _______.
pre-mRNA.
What happens to pre-mRNA in eukaryotes?
It is spliced/introns are removed to form mRNA.
What is translation?
Describe how the production of messenger RNA (mRNA) in a eukaryote cell is different from the production of mRNA in a prokaryote cell.(2)
- Pre-mRNA (only) produced in eukaryote (cell);
- Splicing only occurs in eukaryote (cell);
- Introns removed in eukaryote (cell)
OR Introns not present in prokaryote (cell);
What is a gene? (1)
A sequence of DNA (nucleotides) bases that codes for a polypeptide;
Ignore codes for a protein.
Accept ‘codes for a functional RNA’ or ‘codes for rRNA/tRNAs’ or ‘codes for a sequence of amino acids/primary structure’
Scientists produced a short, single-stranded, artificial nucleic acid, called PNA. The PNA binds to a small section of DNA.
The scientists introduced PNA into cells and discovered that these cells produced less mRNA than cells that did not contain PNA.
Suggest how PNA affected the transcription of the section of DNA. (2)
PNA is complementary to DNA
OR PNA forms base pairs with DNA;
- Preventing/reducing RNA polymerase activity/binding
OR Prevents RNA nucleotides binding
OR Reducing/stopping transcription;
