Chapter 6 Flashcards
(21 cards)
What direction is DNA synthesized?
5’-3’
What does helicase do?
Unwinds DNA strands
What does Topoisomerase do?
Relaxes super coiling
What does DNA polymerase do?
Synthesis new strands
What is a limitation of DNA polymerase?
Requires RNA primers
What does ligase do?
Join fragments of lagging strand (Okazaki Fragments)
What does mRNA do? (Messenger RNA)
Carries information from DNA to ribosome
What does tRNA do? (Transfer RNA)
Binds anti-codons to mRNA
What does rRNA do? (Ribosomal RNA)
Genetic info in ribosomes
What is the purpose of the template strand?
Opposite of correct sequence, ie the template
What are the modifications to the mRNA transcript? (3x)
add poly A tail, add GTP cap, splicing of introns and exons,
What does alternative splicing allow for?
allows for one mRNA sequence to code for multiple genes with inclusion/exclusion of different introns/exons.
What is translation?
The process of mRNA being encoded to a polypeptide chain via ribosomes.
What is the most common stop codon?
UAG
What does the stop codon trigger?
Hydrolysis
What enzyme do retroviruses use to replicate genetic information?
reverse transcriptase
What is the tryptophan operon an example of?
repressible operon
What is the lactose operon an example of?
inducible operon
What are the types of mutations? (3x)
point, framshift, chromosomal
What are the types of point mutations? (3x)
silent, missense, non-sense
What are the types of chromosomal mutations? (4x)
deletion, duplication, inversion, translocation
