DNA

Ayushee Raval

please explain the whole process of DNA replication.

Reply 1

AzureCeleste

Umm no
1. Its your homework probably
2. How much detail? I don't know what level you are studying DNA at

Reply 2

Ayushee Raval

its not my homework actually exams are starting on monday and i need srs help.. btw am in AS level. So please help me out!!
(Original post by AzureCeleste)Umm no
1. Its your homework probably
2. How much detail? I don't know what level you are studying DNA at

Reply 3

AzureCeleste

Original post by Ayushee Raval

Think it through. Get your notes out and look at them
You will benefit far more from working out yourself than me telling you

Reply 4

awbs

i think it's easier to learn and remember through pictures or animations. there's this youtuber called 'Professor Dave Explains' who does videos on this. link: https://www.youtube.com/channel/UC0cd_-e49hZpWLH3UIwoWRA
i'll warn you tho- a lot of them are outdated, but i found the information from it helpful.

anyways, DNA replication was a subject that was largely argued before it's discoverment. many scientists had a hard time believing in how there were only only 4 SIMPLE bases in DNA that coded for the COMPLEXITIES of life.... what were bases these again...?

//history
there were 2 main theories (ones we need to know about) that contributed to the development of it:
conservative & semi-conservative

the conservative theory is associated with WATSON and CRICK and it was called this way because it was though that DNA duplicated from itself orginally.... if thats makes any sense.
basically, it replicated the WHOLE of itself into another copy, and did that again. so it was left with two new conserved dna strands that had not been split at all.

//experiment
however, this theory was proved wrong by STAHL and MESELSON by using the semi conservative experiment. this is where ill tell you to go look it up yourself as its way easier to revise through drawings and pictures, than me telling you. but this experiment showed that dna only kept HALF of itself during replication- which is where the name comes from.

//ACTUALL REPLICATION
in this replication process, an enzyme known as DNA HELICASE unzips the DNA strand by breaking the hydrogen bonds. this creates a replication fork which is basically just the dna strand splitting its legs lol. while its doing this, a primase point on one of the strands attaches a nucleotide primer which is where DNA polymerase will begin to travel along the strands in a 3 prime to 5 prime direction, while making a new strand in the 5 to 3 prime direction.

the reason why i mention the direction is because its important. it confused the **** out of me the first time. its because DNA is 'anitparallel' which just means both strands run in difffernt directions to eachother. one strand is called the LEADING strand while the other is the LAGGING one. polymerase has to break up its work into section when on the lagging strand which is what gave it it's name. this is because it needs a new primer each section (or 'template').

//additionally, if you're curious, the "5 prime and 3 prime" name come from the carbon atoms in the sugar of the nucleotides. the 5th carbon is attached to the phosphate group which attracts to the 3rd carbon making a phosphodiester bond- creating the backbone of the polyNUCLEOTIDE chain... (aka a strand of DNA).

continuing, DNA polymerase gets on the leading strand and creates a series of polymerisation bonds which attach free-floating nucleotides. it creates two bonds: hydrogen and phosphodiester. hydrogen between the bases; phosphodiester between the nucleotides or 5 and 3 prime. this will eventually continue until the last pint where LIGASE goes through the strands ensuring they are all correct.

//extra
the bases in DNA include:

Adedine =Thymine
Guanine = Cytosine

these nitrogem-containing bases are put into two groups: purine & pyrimidine.

purines inlcude adedine and guanine which hold 2 rings inside them, while pyrimidine inlcuding thymine, cytosine and uracil (from rna) have only 1 ring. this is to ensure that the helix can twist naturally without issues.

bleh, im just another student trying to learn just like you so i wouldnt trust everythin im saying. you should go study and revise yourself and come back and prove me wrong :tongue:

Reply 5

Ayushee Raval

Than you so much.. it was really helpful
(Original post by awbs)i think it's easier to learn and remember through pictures or animations. there's this youtuber called 'Professor Dave Explains' who does videos on this. link: https://www.youtube.com/channel/UC0cd_-e49hZpWLH3UIwoWRA
i'll warn you tho- a lot of them are outdated, but i found the information from it helpful.

anyways, DNA replication was a subject that was largely argued before it's discoverment. many scientists had a hard time believing in how there were only only 4 SIMPLE bases in DNA that coded for the COMPLEXITIES of life.... what were bases these again...?

//history
there were 2 main theories (ones we need to know about) that contributed to the development of it:
conservative & semi-conservative

the conservative theory is associated with WATSON and CRICK and it was called this way because it was though that DNA duplicated from itself orginally.... if thats makes any sense.
basically, it replicated the WHOLE of itself into another copy, and did that again. so it was left with two new conserved dna strands that had not been split at all.

//experiment
however, this theory was proved wrong by STAHL and MESELSON by using the semi conservative experiment. this is where ill tell you to go look it up yourself as its way easier to revise through drawings and pictures, than me telling you. but this experiment showed that dna only kept HALF of itself during replication- which is where the name comes from.

//ACTUALL REPLICATION
in this replication process, an enzyme known as DNA HELICASE unzips the DNA strand by breaking the hydrogen bonds. this creates a replication fork which is basically just the dna strand splitting its legs lol. while its doing this, a primase point on one of the strands attaches a nucleotide primer which is where DNA polymerase will begin to travel along the strands in a 3 prime to 5 prime direction, while making a new strand in the 5 to 3 prime direction.

the reason why i mention the direction is because its important. it confused the **** out of me the first time. its because DNA is 'anitparallel' which just means both strands run in difffernt directions to eachother. one strand is called the LEADING strand while the other is the LAGGING one. polymerase has to break up its work into section when on the lagging strand which is what gave it it's name. this is because it needs a new primer each section (or 'template').

//additionally, if you're curious, the "5 prime and 3 prime" name come from the carbon atoms in the sugar of the nucleotides. the 5th carbon is attached to the phosphate group which attracts to the 3rd carbon making a phosphodiester bond- creating the backbone of the polyNUCLEOTIDE chain... (aka a strand of DNA).

continuing, DNA polymerase gets on the leading strand and creates a series of polymerisation bonds which attach free-floating nucleotides. it creates two bonds: hydrogen and phosphodiester. hydrogen between the bases; phosphodiester between the nucleotides or 5 and 3 prime. this will eventually continue until the last pint where LIGASE goes through the strands ensuring they are all correct.

//extra
the bases in DNA include:

Adedine =Thymine
Guanine = Cytosine

these nitrogem-containing bases are put into two groups: purine & pyrimidine.

purines inlcude adedine and guanine which hold 2 rings inside them, while pyrimidine inlcuding thymine, cytosine and uracil (from rna) have only 1 ring. this is to ensure that the helix can twist naturally without issues.

bleh, im just another student trying to learn just like you so i wouldnt trust everythin im saying. you should go study and revise yourself and come back and prove me wrong :tongue:

DNA

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you