DNA replication in Prokaryotes Flashcards
How much nucleotide does a gene have?
1000 nucleotides
How is genetic information contained in E.coli ?
Its contained in a single ,circular DNA molecule (bacterial chromosome)
How are Bacteria reproduced whats the name of the process ?
Binary Fission:
This is where a single cell divides into two identical daughter cells.
Binary fission begins when the the DNA of the bacterium divides in to two replicates.
The bacterial cell then elongates and splits in two daughter cells each with identical DNA to the parent cell.
What does the dna polymerase do in Prokaryotes ?
Adds nucleotides one by one to the growing DNA chain that are complementary to the template strand.
What does the addition of nucleotides require ?
Requires energy , this energy is obtained from nucleotides that have three phosphates attached to them ,similar to ATP which has three phosphate groups attached .
When the bonds is broken its used to form phosphor di ester bonds between the incoming nucleotide and the growing chain
What are the enzyme needed for DNA synthesisand how many ?
DNA pol, DNA pol 11 are reuired for repair
What is the Function of DNA polymerase 1 ?
The physiological function of Pol I is mainly to repair any damage with DNA, but it also serves to connect Okazaki fragments by deleting RNA primers and replacing the strand with DNA.
What is the function of DNA polymerase 2 ?
the PolB protein.
Repair function
What is the function of DNA polymerase 3 ?
is the enzyme that performs the 5’-3’ polymerase function.
What happens before each cell division ?
Strands are replicated doubling the DNA content .
What do we mean by Semi conservative ?
Separating strands into different strands which separate .This starts with one DNA molecule, Produces tow daughter molecules. Each daughter cell has one new strand and old strand.
First step of DNA replication
The two strands of helix have to be separated to allow binding of the replication .Occurring through binding of the enzyme DNA helicase .This enzyme then detaches the strand by splitting hydrogen bonds.
Second Step of DNA replication ?
The dna helicase act as a specific region .
DNA is called origins of replication
The unwinding of the two strands by DNA helicase creates a Y shape /structure .In which single strand DNA
Third Strand of DNA replication
The helicase moves along the strands creating a replication bubble .
The seperates strands provide a template for synthesising a new strand.
Proteins called single strand binding proteins coat the separated strands keeping them from reforming double helix .
Four step of DNA replication
An enzyme known as promarse makes a small piece of RNA called primer ,makrs the starting poiny for the synthesis of new strand.
In addition, another enzyme known as DNA polymerase binds to primer and begins the synthesis of new strand.This enzyme is primarily responsible for the synthesis DNA incorporating complementary nucleotides one by one on the growing chain.
