Can someone pleeeeaaaaase explain transcription and translation to me?

Question

ok so i know that in transcription mRNA is transcribed from DNA and in translation protein is made from mRNA. In transcription the DNA uncoils and "unzips" and then...ummm...nucleotides attach on to the DNA strand? and in translation the mRNA attaches to the ribosome and then the tRNA brings anti-codons and amino acids and then it becomes an amino acid chain attached by peptide bonds? is that right?

Answer 1

You have it right, but I have the feeling you can't picture it. Try looking at some animations available online.

http://ull.chemistry.uakron.edu/genobc/animations/protein.mov

http://www.westga.edu/~lkral/prtsynth/prtsynth.mov


http://www.mhhe.com/biosci/esp/2002_general/Esp/folder_structure/le/m6/s5/lem6s5_10.htm

Answer 2

Here is the more clear info to clarify ur doubts:
Transcription is the process through which a DNA sequence is enzymatically copied by an RNA polymerase to produce a complementary RNA. Or, in other words, the transfer of genetic information from DNA into RNA. In the case of protein-encoding DNA, transcription is the beginning of the process that ultimately leads to the translation of the genetic code (via the mRNA intermediate) into a functional peptide or protein. The stretch of DNA that is transcribed into an RNA molecule is called transcription unit. Transcription has some proofreading mechanisms, but they are fewer and less effective than the controls for DNA; therefore, transcription has a lower copying fidelity than DNA replication.
As in DNA replication, transcription proceeds in the 5' → 3' direction (ie the old polymer is read in the 3' → 5' direction and the new, complementary fragments are generated in the 5' → 3' direction). Transcription is divided into 3 stages: initiation, elongation and termination.

Initiation
RNA polymerase binds to the promoter in DNA possibly with the help of sigma factor. Unlike DNA replication, transcription does not need a primer to start. The DNA unwinds and produces a small open complex and synthesis begins on only the template strand.


Elongation
Unlike DNA replication, mRNA transcription can involve multiple RNA polymerases, so large amounts of the gene can be made from the single transcript. This step also involves a proofreading mechanism that can replace an incorrectly added mRNA.


Termination
Upon seeing a termination codon within the DNA template, RNA transcription can stop by forming a secondary hairpin loop that lets it comes off the DNA template. Also, another protein designed "Rho" can pull the mRNA away from polymerase.


Translation is the second process of protein biosynthesis (part of the overall process of gene expression).Translation occurs in the cytoplasm where the ribosomes are located. Ribosomes are made of a small and large subunit which surrounds the mRNA. In translation, messenger RNA (mRNA) is decoded to produce a specific polypeptide according to the rules specified by the genetic code. This is the process that converts an mRNA sequence into a chain of amino acids that form a protein. Translation is necessarily preceded by transcription. Translation proceeds in four phases: activation, initiation, elongation and termination (all describing the growth of the amino acid chain, or polypeptide that is the product of translation).

In activation, the correct amino acid (AA) is joined to the correct transfer RNA (tRNA). While this is not technically a step in translation, it is required for translation to proceed. The AA is joined by its carboxyl group to the 3' OH of the tRNA by an ester bond. When the tRNA has an amino acid linked to it, it is termed "charged".
Initiation involves the small subunit of the ribosome binding to 5' end of mRNA with the help of initiation factors (IF), other proteins that assist the process.
Elongation occurs when the next aminoacyl-tRNA (charged tRNA) in line binds to the ribosome along with GTP and an elongation factor.
Termination of the polypeptide happens when the A site of the ribosome faces a stop (nonsense) codon (UAA, UAG, or UGA). When this happens, no tRNA can recognize it, but releasing factor can recognize nonsense codons and causes the release of the polypeptide chain. The capacity of disabling or inhibiting translation in protein biosynthesis is used by antibiotics such as: anisomycin, cycloheximide, chloramphenicol and tetracycline.