Author Topic: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!  (Read 965 times)

Offline Kim

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AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« on: January 11, 2010, 04:44:49 pm »
hey u guys
if sum1 could explain nucleotides and the translation transcription thingy it would be really appreciated by me!!!!!!!!!!!!!!!!!!!
thanks in advance
Take care ;D
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Offline Kim

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #1 on: January 11, 2010, 04:49:22 pm »
cum on ppl no1???
i feel like i am the only one who does Edexcel A level in this whole forum!!!!!!!

   "i m mr lonely oh so lonely i m all alone"
After all is said and done, more is said than done.

By the time a man realizes that maybe his father was right, he usually has a son who thinks he’s wrong.

The early bird may get the worm, but the second mouse gets the cheese.

Offline Saladin

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #2 on: January 11, 2010, 04:52:33 pm »
A neucleotide is a compound i.e. chemical that is a part of RNA or DNA. The distinct part of it is that it has phosphate in its forumula.

Offline Kim

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #3 on: January 11, 2010, 04:54:08 pm »
A neucleotide is a compound i.e. chemical that is a part of RNA or DNA. The distinct part of it is that it has phosphate in its forumula.

hey thanks but my main problem was the second part!!!!!!!!!!!!hehe
oh well thanks again
After all is said and done, more is said than done.

By the time a man realizes that maybe his father was right, he usually has a son who thinks he’s wrong.

The early bird may get the worm, but the second mouse gets the cheese.

Offline examsaresoon

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #4 on: January 11, 2010, 05:20:49 pm »
Transcription
. The DNA strand seperates by action of RNA polymerase.
. The hyrdogen bonds break apart.
. The free nucleotides in the cytoplasm of the cell gather acording to their complimentary base pairs and join them
. This prouduces a strand of mRNA.
. The mRNA then leaves the nucleous and goes to the cytoplasm.

Translation.
. The mRNA attaches it self to a ribosome.
. A tRNA then comes and its anti-codon matches up with its complimentory base pairs.
. The Aminoacid groups at the end of the tRNA join, by peptide linkage.
. This contines till the STOP codon.

Hope this is correct!

Offline Dreams <3

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #5 on: January 11, 2010, 05:26:41 pm »
Transcrption:
-when RNA polymerase attached to the double helix of the DNA in a region of the gene that is being expressed
-hydrogen bonds are broken down, part of DNA unwinds
-a strand acts as a template and is copied by base pairing nucleotides so a complemantary polyneucleotide strand of mRNA (caused by RNA polymerase)
-mRNA is detached from the coding strand of DNA, it leaves the nucleus through pores into the cytoplasm to the ribosomes.

Translation:
-mRNA attaches to the ribosomes and held in such a way that codons are exposed
-tRNA carry a specific amino acid
-anticodons on tRNA bind to codons on mRNA forming peptide bond between amino acises
(ribosomes move relative to mRNA until a stop codon is reached)

Hope I helped

Offline Kim

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Re: AS biology edexcel help!!!!!!!!!!!!!!!!!!!!!!!!!!!!
« Reply #6 on: January 11, 2010, 05:51:40 pm »
hey u guyz thank u so much!!!!!!!!!!!!
u guyz are life savers
ROCK ON!
After all is said and done, more is said than done.

By the time a man realizes that maybe his father was right, he usually has a son who thinks he’s wrong.

The early bird may get the worm, but the second mouse gets the cheese.