DNA is copied into a complementary mRNA, then the mRNA IS delivered to the ribosomes in the cytoplasm
RNA polymerase binds to the promoter region at the TATA box and begins uncoiling
RNA polymerase makes a copy of the template strand in the 5 prime to 3 prime direction
The DNA strand that is not being copied, but contains the same sequence as the new RNA molecule
Transcription is terminated when the RNA polymerase recognizes a termination sequence
Termination in prokaryotes
Transcription may be stopped by a protein binding the mRNA, or by the mRNA twisting itself into a loop
Termination in eukaryotes
A termination sequence may be a string of adenines, which will bind to the proteins and transcription stops
Capping & tailing
Poly-A tail is added to the 3 prime end of the mRNA to protect it from being digested or damaged. The 5 prime cap is also added.
5 prime cap
A chain of seven guanines used at the initial site for attachment of mRNA's and the ribosomes
A process that produces different mRNA's from the removal of introns and combining of exons. This allows more than one polypeptide to be made from one gene.
The complementary sequence of base pairs on a tRNA that corresponds to the codons of the mRNA.
Precursor mRNA are made of exons and introns. Are the immature and vulnerable single strand mRNA
States that the rules of base pairing are relaxed at the third position, so that a base can pair with more than one complementary base
A codon that causes the ribosome to terminate translation by signalling the end of a polypeptide
During translation amino acids are linked together to form a polypeptide chain which will later be folded into a protein.
Ribosomes bind to the mRNA, recognizing the 5 prime cap. Meth-tRNA starts the translation by joining the small ribosomal subunit and scanning the mRNA until it reaches the start codon. Large ribosomal subunits then bind to complete the ribosome
A new tRNA+amino acid enters the ribosome, at the next codon downstream of the current codon. If the anticodon matches the mRNA codon, base pairs and the ribosome can link the two amino acids together. The empty tRNA moves to the E site and is released.
Termination of a polypeptide chain occurs when the ribosome encounters a stop codon at the A site. Polypeptide is released and ribosomal subunits separate.
A complex formed when multiple ribosomes attach to the same mRNA to facilitate rapid translation
A cluster of genes on a bacterial chromosome that is connected by one promoter and one operator
Binds to the operator and blocking the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes