ocr a transcription and translation (a level)

Watch this thread
username5809028
Badges: 11
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 1 month ago
#1
hii,
can someone please explain transcription and translation to me please
0
reply
TheTrueFarhan
Badges: 4
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 1 month ago
#2
Ooo okay this is one topic I haven't revisited in quite some time but will be good revision for me I guess hahahah. So here goes:

Transcription happens first to put the DNA in a language the ribosomes can understand so they can make the protein. The RNA polymerase reads the DNA in a 3' to 5' direction and makes pre-messenger RNA (pre-mRNA) by base pairing complementary nucleotides like A on DNA to U on RNA and vice versa, and C on DNA to G on RNA. Once done, this pre-mRNA undergoes processing to become a mature RNA that ribosomes can finally read. If it was not mature, it would be degraded in such a short time that none of it would get read and no proteins would be made to make any significant difference...
So, the pre-mRNA gets a 5' cap (methylated guanine) added, and a polyadenine tail at the 3' end (AAAAAAAAAAAA....) and gets its introns excised so only the coding exons remain. This means when the RNA is translated, it can remain in the cytoplasm of the cell for a longer time and not get degraded as the 5' cap stops exonucleases from removing nucleotides at the ends to degrade it! In addition, the coding sequence now consists of exons only so the whole mRNA is now useful coding sequence, and can make a functional protein. This is now called mature mRNA.

Afterwards, this mature mRNA leaves the nucleus and enters the cytoplasm where ribosomes are, and they basically attach to the 5' cap to read the mature mRNA and its continuous coding sequence, in groups of 3 called triplets or codons. Each 3 codons code for a separate amino acid, with one start codon (AUG for methionine) and 3 stop codons (UAG, UGA, UAA). While the mRNA is being read codon by codon, different transfer RNA (tRNA) brings amino acids required to the ribosome, and peptidyltransferase (an enzyme in the large ribosomal subunit) helps form peptide bonds between amino acids to make a polypeptide chain. Once the mRNA is fully read and a stop codon is reached, some proteins come and cleave the polypeptide chain.

This chain then folds and bends to get a primary, secondary, tertiary or even quaternary structure and is now a fully functional protein
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest

How are you feeling about your results?

They're better than I expected (46)
37.7%
They're exactly what I expected (30)
24.59%
They're lower than I expected (46)
37.7%

Watched Threads

View All