What is the first step of DNA replication?

Question

Help me out here!!

Answer 1

The first step in DNA replication is trascription. This is where a RNA polymerace comes and attaches to the promoter non-codon region directly before a gene. The RNA polymerase does not require RNA primer to start coding as does DNA polymerase 3 during DNA replication. There is the template DNA by which the RNA polymerase fashions the complimentary strands of nucleotide bases. Say the the template DNA is like A-G-T-C-A-T-C-C-C-A-T-G-A-A, then the RNA replaces Adenine with Uracile(acts in the same complementary fashion as Thymine) and Guanine with Cytosine, and as such the complementary mRNA would look U-C-A-G-U-A-G-G-G-U-A-C-U-U, as the RNA polymerase has unwinded and finish replicating particular sections of the gene, the DNA rewinds itself into a double helix structure. As the RNA polymerase then reaches a termination sequence upon the gene signalling the end of the genewhich is also non-coding region, and it deattaches from the DNA resulting in the replicated gene mRNA strand and the RNA polymerase will continue its work by replicating even more copies of the same particular gene. This all takes place within the nucleus of the cell, and mRNA is created so that the DNA material is not itself harmed in the protein synthesis process. The mRNA is not yet completely finished, as there are many noncoding sections that are cut out call exons, and all the introns are then glue together. exons-intron-intron-intron-exon-exon, finshed result is intron-intron-intron coding sections. A poly adenine tail is also added, before the mRNA exist the nucleus for the process of protein sysnthesis and trslation in the ribosomes of the cell. There are three distinct differences between mRNA and DNA itself. First mRNA is not double stranted but single stranted unlike DNA. And in DNA where Thymine acts complimentary to Adenine, in mRNA,Uracil is complimentary to Adenine, and also the mRNA is ribose and not deoxiribose unlike DNA because it has a OH- near its end 5' to 3' prime end. Get more details and info at wikipedia and other biology links. And as described one replication does not happen at a time, but many RNA polymerase make many duplicates for the systhesis of the same gene and protein.

Answer 2

Initiation is the first step. In bacteria there is an AT rich region that must first be bound it is the ORI(origin of replication). Your smaller DNA polymerase subunit scans the DNA looking for these sites and binds first.

There are excellent textbooks you can find at the NCBI database that have all the information you could want. They are included in the link. Good Luck.

Answer 3

step a million: enzyme unwinds and separates DNA strand step 2: 2 seperate DNA strands grow to be templates for brand spanking new strand step 3: different ends of DNA (A for T, G for C, and vice versa) fall into position step 4: DNA bonded mutually, 2 new strands formed

Answer 4

seperation of the DNA double helix

Answer 5

The unwinding of the double helix

Answer 6

a DNA sample

Answer 7

Brownian motion.

Answer 8

the process of mitosis..