What prevents the wrong nucleotide from being added to the new strand during DNA replication?
DNA polymerase 3 and DNA polymerase 1 can become what is known as exonucleases. an exonuclease can go back and "proofread" the replicated DNA and if there is a mistake, then everything beyond that incorrect nucleotide is removed and the DNA polymerase 3 will re-replicate from the bad point on.
the protein p53 holds the cell in the G1 and S phase of replication which allows more time for proof reading the replicated DNA
After DNA is unwound and split by a protein called helicase. Behind the helicase is another protein called single strand binding protein (SSB) which keeps the separated strands from reannealing.
On the leading strand, replication occurs immediately after helicase splits the two strands, so there is not chance for the strands to reattach. On the other strand, the lagging strand, there is a delay of about 1 second (1000 base pairs) before the strand is replicated, which is an extremely long time in biochemical terms. Another protein, known as Single Stranded Binding protein (SSB) in E. coli (it goes by other names in other organisms but does the same job) binds to the single stranded DNA strand to prevent it reannealing with itself. SSB is displaced, when access to the single straded DNA is needed, by a subunit of DNA polymerase.
single-stranded binding proteins
single-strand binding proteins
Hydrogen bonds
The two strands of DNA are held together by hydrogen bonds.
Single Strand Binding Proteins
Nucleus - holds genomic DNA in eukaryotes. The nucleus is the most conspicuous organelle found in a eukaryotic cell. It houses the cell's chromosomes and is the place where almost all DNA replication and RNA synthesis occur.
The centromere is the region of the chromosome that holds the two sister chromatids together during mitosis. The chromatid is one of the two strands of chromosomes that become visible during mitosis or meiosis.
Centremere?
What prevents the wrong nucleotide from being added to the new strand during DNA replication? DNA polymerase 3 and DNA polymerase 1 can become what is known as exonucleases. an exonuclease can go back and "proofread" the replicated DNA and if there is a mistake, then everything beyond that incorrect nucleotide is removed and the DNA polymerase 3 will re-replicate from the bad point on. the protein p53 holds the cell in the G1 and S phase of replication which allows more time for proof reading the replicated DNA
Hydrogen bonding.
hydrogen bonds
hydrogen bonds
Hydrogen bonds.
hydrogen bonds
hydrogen bonds
hydrogen bonds
Hydrogen bonds
hydrogen bonds
Hydrogen bonds and the hydrophobic effect