Cell Cycle/DNA Flashcards
(33 cards)
In DNA replication, which enzyme joins fragments of DNA? What are the fragments called?
Okazaki fragments
DNA ligase
In which direction does DNA polymerase READ the template strand?
3’ to 5’
What happens in termination stage of DNA replication?
RNA primers removed and so DNA polymerase dissociates
Why is DNA replication described as semi-conservative?
In the 2 daughter copies of the original DNA, 1 strand is original and 1 strand is new
What enzyme lays down which sort of primers in DNA replication?
RNA primase
RNA primers
At which stage of the cell cycle do chromosomes replicate?
S phase
When writing two strands of DNA nucleotides, conventionally, which strand is on the top?
Coding strand (going from 5’–>3’)
In which direction does DNA polymerase synthesise the new strand?
5’ to 3’
What promoter sequence is used/recognised in eukaryotes?
TATA box (at -30)
What promoter sequence is recognised in prokaryotes?
Prob now box (at -10)
What type of ribosomes are present in eukaryotes?
80s, has 40s + 60s sub units
What ribosomes are present in prokaryotes? What sub units have they?
70s, have 30s + 50s sub units
Which direction does RNA polymerase read the template strand in?
3’ to 5’
TF producing new strand in 5’ to 3’
List three types of RNA processing occuring in eukaryotic pre-mRNA.
Splicing, 5’ capping, 3’ tailing
What does 5’ capping do?
Adds special 5’ cap which protects from degradation
What does 3’ tailing do? Another name?
Polyadenylation, adds poly A tail onto 3’ end, protects against degradation.
What does splicing do? Why important?
Remove selected introns, allows different levels of regulation of gene expression
What is the initiation codon for translation? Which amino acid does this code for?
AUG, codes for methionine
What is the ‘wobble position’? Why is it important?
The third position in a codon. Once the first two bases have been paired correctly, whether the third is paired precisely is les important. Allows one tRNA to recognise several codons.
Which enzyme makes the peptide bond between AA’s in translation?
Peptides transferase
What is another name for the template strand? What clue does it give us to its function?
Non-coding strand- TF it doesn’t code for mRNA
What are the phases of the cell cycle?
Interphase, Mitosis
What are the 5 stages of mitosis?
Prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
What are the stages of interphase?
G1, S phase, G2
