Transcription Process

8 Questions

To catalyze the formation of phosphodiester bonds

To align free nucleotides for mRNA synthesis

It re-forms its double helix structure

To carry amino acids to the ribosome

A polypeptide chain is formed

To facilitate the formation of a polypeptide chain

Translation ceases and the process ends

It is spliced to remove introns

Study Notes

During transcription, an mRNA molecule is created in the nucleus through a process involving DNA uncoiling, nucleotide pairing, and phosphodiester bond formation.
Hydrogen bonds between complementary bases break, and one DNA strand serves as a template (antisense strand) for mRNA formation.
Free nucleotides line up through complementary base pairing and are joined by phosphodiester bonds, forming an mRNA molecule, catalyzed by RNA polymerase.
When a stop codon is reached, transcription ceases, and the RNA polymerase moves away, allowing the DNA to rejoin.

In eukaryotic cells, the pre-mRNA undergoes splicing to remove introns, leaving a strand of exons.
The mRNA then exits the nucleus through a pore and attaches to a ribosome in the cytoplasm.

In translation, amino acids join to form a polypeptide chain through a process involving mRNA, ribosomes, and transfer RNA (tRNA).
mRNA attaches to a ribosome, and tRNA collects amino acids from the cytoplasm, carrying them to the ribosome.
tRNA attaches itself to mRNA through complementary base pairing, and amino acids join by a peptide bond, releasing the tRNA.
This process repeats until a stop codon is reached, ending protein synthesis.
A ribosome can join up to 15 amino acids per second, and multiple ribosomes can move along the same mRNA strand, assembling proteins simultaneously.