DNA Quiz Flashcards
What enzyme adds nucleotides to the DNA strand?
DNA polymerase
What enzyme unwinds DNA to form a replication fork?
Helicase
Which strand shows discontinuous synthesis?
Lagging strand
What enzyme replaces RNA with DNA to form double stranded DNA?
DNA polymerase
What is the main difference between eukaryotic and prokaryotic replication?
Eukaryotic have more then one origin of replication and its a slower process than prokaryotic replication
What is a codon?
Sequence of 3 nucleotides in mRNA
What type of mutation is THE-CAT-SAT-MAT to HEC-ATS-ATM-ATX?
Frameshift mutation whether one nucleotide as been added or removed causing the grouping of nucleotides into codons shift
mRNA most ressembles the template or coding strand?
Coding strand
During transcription new NTPs are added at the 5’ or 3’ end?
3’ end since it binds with the hydroxyl group of the previous nucleotide
What is added to the beginning and end of a mature transcript?
Beginning: 5’ cap
End: 3’ poly-A tail
Which is coding exon or intron?
Exons
What stops transcription?
Terminator sequence
What stops translation?
A stop codon (UAA, UAG, UGA)
What does interfering RNA do?
Regulates gene expression and protects cells from viral infections
What enzyme cuts DNA to make sticky ends?
Restriction enzyme (endonuclease)
How bacteria uses restriction enzymes?
As a defense mechanism to protect themselves from foreign DNA such as bacteriaphages
What is the small circular replicating section of DNA in bacterium?
Plasmids
How the lacZ gene used to detect recombinant DNA?
Reporter gene to detect recombinant DNA, lacZ encodes the enzyme beta galactosidase which breaks down a specific substrate
*Identify bacterial cells that contain recombinant DNA
How is antibiotic resistance used to check whether bacteria have been transformed?
Cause it confers ampicillin and allow the cell to grow on ampicillin containing medium, since transformed bacteria are the only one that have plasmid and AmpR is within the plasmid
What are the 3 main steps of PCR?
1-Denaturation
2-Annealing
3-DNA synthesis
What is a DNA probe?
Single-stranded segment of DNA that is used to detect the presence of a specific complementary sequence of nucleotides in a sample of DNA or RNA
What is the name of the positively charged proteins that organise chromatin structure?
Histones
What is an operon?
Is a cluster of genes in prokaryotic cells that are transcribed together from a single promoter as a single mRNA molecule.
What is a snRNP?
Small nuclear ribonucleoprotein is a complex of small RNA molecule and proteins that plays a critical role in the splicing of pre-mRNA in eukaryotic cells
