MBG PART TWO: Lecture 1 Flashcards
What is the Central Dogma of Molecular Biology?
The flow of genetic information from DNA to mRNA to a Protein using transcription and translation
What is the error rate when a cell divides?
A low error rate of 1 in a million
would result in 6,400 mistakes every time a cell divide
What is E.coli replication rate?
1000 nucleotides per second with an error rate of less than 1 in a billion. nucleotides.
What did the Watson Crick Model Suggest?
DNA replication is semi conservative
What is the end product of DNA semi conservative DNA synthesis
After one round of DNA replication, each DNA contains 1 parental and 1
newly-synthesized strand
What did the conservative model suggest?
The parent is being maintained throughout
What did the dispersive model suggest?
Patches throughout
How do prokaryotes replicate?
Through F Factors or Plasmids.
How do Eukaryotes replicate?
From Cell to Nucleus to Chromosome to DNA
What is Theta Replication?
Replication that occurs in most circular DNA (bacteria) with only 1 origin of replication
Describe the Steps of Theta Replication.
1.) Double Stranded DNA unwinds at the replication origin
2.) This produces single stranded templates for the synthesis of new DNA. A replication bubble forms, usually at the end of the replication fork at each end.
3.) The forks proceed around the circle
4.) Eventually two circular DNA molecules are produced.
What is Rolling Stone Replication?
Specialized form of replication that occurs in the F factor of E.coli and some viruses
Describe the events of Rolling Stone Replication.
1.) Replication is initiated by a break in one of the nucleotide strands
2.) DNA synthesis begins at the 3’ end of the broken strand; the inner strand is used as a template. The 5’ end of the broken strand is displaced.
3.) Cleavage releases a single stranded linear DNA and a double stranded circular DNA
4.) The linear DNA may circularize and serve as a template for synthesis of a complementary strand.
What is Linear Chromosome Replication?
Occurs in the linear chromosomes of Eukaryotic Cells.
Describe the events of Linear Chromosome replication.
1.) Each chromosomes contain numerous origins
2.) At each origin, the DNA unwinds, producing. replication bubble.
3.) DNA synthesis takes place on birth strands at each end of the bubble as the replication forks proceed outwards.
4.) Eventually, the forks of adjacent bubbles run into each other and the segments of DNA fuse
5.) This produces two identical linear DNA molecules.
