Question

How does DNA code for proteins in a cell?

a. by creating a new double helix structure
b. by using phosphate and sugar molecules
c. by adding more ydrogen bonds to it's structure
d. by arranging certain nitrogen bases of the cell in particular order

and please explain this to me

Answer 1

I personally dont know.. i have a couple links that may.

Answer 2

ok, where are those links?

Answer 3

Try here: http://www.science-explained.com/theory/dna-rna-and-protein/ it explains

Answer 4

i'll try to explain it stepwise but its quite big
i'll start from transcription all the way to translation

Answer 5

then you can get your answer from it
so
Step 1 DNA transription
transcription is making of mRNA using DNA strand as a template
Step 2 Translation
now this is quiet big
once mRNA is made in the nucleus - it leaves the nucleus through nuclear pores and goes to ribosomes of either cytoplasm or rough endoplasmic reticulum
so
here the translation takes place
now i will tell you what DNA is composed of to get you to understand whats gonna happen
now DNA is composed of Phosphate backbone, deoxyribose sugar and nitrogenous bases (Adenine, Thymine, Guanine and Cytosine)
so each of the strands of DNA are connected to each other by hydrogen bonds between nitrogenous bases = and thus the helix is formed
this bond is formed between complementary bases meaning Adenine always pairs with Thymine and Guanine always pairs with Cytosine
lets represent each of these bases by A for adenine, T for thymine, G for guanine and C for cytosine

so one DNA strand will have a looooot of these ATTGCACCTGGGAAT bluh blah as one whooooole strand
and this strand has its complementary strand
now
these ATGGCACCTGGGAAT bluh blah are actually information stored in DNA
3 of these bases for ex. ATG code for 1 amino acid - this is so called triplet code
this triplet code when transcribed to make mRNA changes to complementary bases for that code
so from ATG to UAC (U instead of T because mRNA has U instead of T)
and this UAC is called a codon!
now this travels outside nucleus to be translated

tRNA - this is transfer RNA
it brings AMINO ACIDS WITH anticodon belonging to that particular amino acid it is bringing
so tRNA would bring amino acid Thyrosine that is coded as UAC in mRNA and so tRNA will have anticodon as AUG

okay so now that you know about amino acids and codons lets finally talk about translation
so this mRNA strand comes and binds to a ribosome
now both subunits of ribosome are bound to it and we are ready to stard translation as soon as tRNA comes
so tRNA came with anticodon AUG
now it will match it with mRNA codons and find its own
as its turn comes (which doesnt take too long as its pretty fast) it will enter the ribosome match its anticodon to the codon and if it matches then leave the amino acids in there and then leave the ribosome itself
now next tRNA comes with anticodon and same thing happens
as more and more tRNA comes - all amino acids are left and simultaneously as each amino acid is left it forms a peptide bond with the polypeptide chain that is growing
it will continue till STOP codon on mRNA reaches
as soon as stop codon is detected - translation stops and ribosome breaks down to its usual bigger and smaller subunits and mRNA is let out to cytoplasm and finished polypeptide/protein is now formed
(translation always starts from 1 start codon! and ends with one of 3 types of stop codons)

thats about it
tried to summarize it as as short as i could
there is more detail to each of the processes so if you are interested - check out youtube by searching DNA transcription/Translation or Protein synthesis animations

now you can conclude your answer