Unit 4 Flashcards
Ligase
Repairs nicks by linking sugars through bonds with phosphate groups.
DNA Polymerase III
Extends the new strand by attaching complementary nucleotides to the template DNA.
DNA Polymerase I
Removes the primer and replaces it with DNA nucleotides.
Topoiosmerase
Relieves super-coiling upstream of the origin of replication.
New strands of DNA are synthesized in which direction?
5’ to 3’
Meselson and Stalh’s experiments proved that DNA replicates by which mode?
Semi-conservative
The ends of a chromosome are protected by the presence of
Telomeres
The enzyme helicase
Separates the 2 DNA strands of the double helix
Which would you expect of a eukaryotic organism lacking telomerase
a reduction of chromosome length in gametes (I’m not 100% sure on this one)
A poly-A sequence is added at the:
3’ end of transcribed mRNA in the nucleus
How many nucleotides are in 12 mRNA codons?
36
The AUC and AUA codons in mRNA both specify isoleucine. What features of the genetic code explains this?
the tRNA wobble
Which best describes introns?
untranslated DNA sequences in a gene
What is often the first amino acid added to the polypeptide chain?
Methionine
What are the RNA components of ribosomes called?
rRNA