Diploma Prep: DNA Flashcards
What is the structure of DNA?
double helix, ATCG, dioxyribose, phosphorus
How are nucleosomes formed?
winding DNA around histones
What did Franklin contribute to discovering the structure of DNA?
x-ray crystallography
What did Watson and Crick contribute to discovering the structure of DNA?
discovered the double helix
What is the role of helicase in dna replication?
unwinds two strands
What is the role of single stranded binding proteins in dna replication?
stabilizes dna to keep it open
What is the role of rna primase in dna replication?
builds short sections of rna primer, provides attachment site for dna polymerase 3
What is the role of dna polymerase 3 in dna replication?
attaches to rna primer and adds complimentary nucleotides
What is the role of dna polymerase 1 in dna replication?
replaces rna primers with base pairs
What is the role of dna ligase in dna replication?
glues fragments together
What is gel electrophoresis, how is it performed and what is it used for?
dna is put with restriction enzymes and put in a gel medium with a current, dna is - and so the smallest pieces of dna move the fastest, used in parental testing and forensics
What are the steps in dna recombination?
- isolate gene (w restriction enzymes)
- restriction enzyme cuts plasmid - cant cut on binding site or inside antibacterial resistance code
- grow bacteria on agar with antibiotic
What are the differences between dna and rna?
rna is single stranded, rna uses uracil instead of thymine, rna uses ribose
What are the steps of rna transcription and what do they do?
- initiation (rna polymerase opens double helix and reads 3’ strand)
- elongation (rna nucleotides are placed)
- termination (mRNA falls off when it hits the terminator
What happens to rna after transcription?
methyl cap is added, poly-a tail is added, non-coding rna is taken out (introns)