Help! DNA replication (1 Viewer)

[Leap]

I've never understood the whole DNA replication thing in part 4 of Blueprint of life - the syllabus point is:

describe the process of DNA replication and explain its significance

Can anyone explain this in simple terms?

 

[crazylilmonkee]

umm.. well all i can think of is how the DNA unzips it self and seperates as two strands.. then the complementary sides form so then there are two strands of identical DNA.. this is significant as it can make identical copies of the gene..

 

[elizabethy]

the significance of dna replication is that identical copies of the genes can be made.

 

[~Dreamer]

dna unzips into 2 strands, then free nucleotides come and fill gaps in each of strand lecing 2 indentical strands...identical copy is significant as,lil monkey said, makes identical copy of gene which can be passed on,

 

[tempco]

theres an enzyme which joins the nucleotides together.. can't remember.. i think it was DNA ligase.. or was it DNA polymerase?

weh... i'm confused :S

 

[crazylilmonkee]

isnt DNA ligase for the recombiant DNA when they are annealed?

 

[Leap]

Originally posted by crazylilmonkee
isnt DNA ligase for the recombiant DNA when they are annealed?

I have no idea what that meants - say it in English please!

 

[jims]

ligase are a class of enzymes which basically join molecules together. so yeh they use a ligase enzyme for recDNA but thats probably a different enzyme to the one involved in DNA replication.

 

[Nicolejellybean]

Protein Sythesis
TRANSCRIPTION
1) Dna chain unzips (catalysed by polymerase)
2) free nucleotides attach to their corrosponding bases (ie C+G, A+T)
*note at this stage there is no T (only U) thus a U will come along to join an A THERE ARE NO T's IN THIS PROCESS EXCEPT 4 WHATS ON THE UNZIPPED DNA STRAND)
3) once bases are linked up it is called an MRNA strand. This strand then goes into the cytoplasm via the ribosomes
TRANSLOCATION
4) In the cytoplasm TRNA join onto the MRNA strand (reflection or template of the DNA strand) the TRNA have an amino acid attached
5) When its all in place the amino acids link up to form a pollypeptide bond
6) the result is a protein molecule, i unattached and more protein molecules are manufactured begining at the Translocation phase

 

[tempco]

Originally posted by jims
ligase are a class of enzymes which basically join molecules together. so yeh they use a ligase enzyme for recDNA but thats probably a different enzyme to the one involved in DNA replication.

Yeh... it's DNA polymerase that is responsible for DNA replication...

http://www.rcsb.org/pdb/molecules/pdb3_1.html

That's what it says there.. don't know exactly what it does though :/

 

[mei_ling03]

protein synthesis is not DNA replication
1. DNA unzips (breakage of the bonds between each base pair), forming a replication fork. special binding proteins prevent the strands from reforming
2. complementary bases join onto each strand (A,T,C,G). this process is catalsed by the enzyme polymerase.
3. result: 2 DNA strands are formed.

significance: during resting phase, when the cell is not dividing, the DNA must undergo replication (so there is sufficient DNA provided in each of the daughter cells). in meiosis/mitosis, the unzipping of the DNA is actually the separation of the chromatids. this process is important in reproduction, growth and repair.
just think of the bundles in the first stage of meiosis - that's where DNA is replicated.