Involves the interactions of mRNA, tRNA, ribosomes and several transciption factors.
Some ribosomes attached to membranes (rough endoplasmic reticulum), others not attached (free ribosomes)
mRNA leaves the Nucleus and Looks for a Ribosome
After the code is transcribed the m-RNA is further processed: special head and tail regions are added and some parts are spliced out
RNA leaves the nucleus and carries the code into the cytoplasm, then attaches to a ribosome
The RNA Code is Translated into Protein
Ribosome finds start codon (AUG), then decodes the message, 3 bases at a time
When the ribosome reaches the stop codon the protein is released and the decoding can start over to make another protein
mRNA carries the genes.
The sequence of mRNA strand is complementary to that of DNA.
Leaves the nuc – cyto to encounter ribosomes.
Triplet codon specifies a certain protein in the sequence of amino acids
Dictates the production of proteins by ribosomes .
Anticodon is complementary to the codons on mRNA held by H+ bonds.
Peptidyl transferase catalyses the formation of peptide bond between 2 amino acids.
Once the amino acids have joined, tRNA molecules are released
Base pairing between the codons of mRNA and the anticodons on tRNA mol ensures that the transcribed info is translated into the correct sequence of amino acid.
ribosomes move along the mRNA molecule and "read" its sequence 3 nucleotides at a time (codon) from the 5' end to the 3' end.
Each amino acid is specified by the mRNA's codon, and then pairs with a sequence of three complementary nucleotides carried by a particular tRNA (anticodon).
Several ribosomes can attach to an mRNA strand simultaneously, forming polysomes .
This speeds up the generation of large number of polypeptides.
Summary Ribosome decodes the m-RNA and makes the correct protein. m-RNA Ribosomes Peptidyl transferase enzyme Transfer RNAs In the cytoplasm, on the ribosomes Translation Gene is activated. A copy of the code is made from RNA (m-RNA) m-RNA leaves the nucleus, goes to cytoplasm. DNA gene RNA polymerase In the nucleus Transcription Notes Major Components Where Process
20 a2 serve as subunits
Each amino acid has a carboxyl group, amino group, and a radical group R
All bound covalently to a central C.
R group gives each a2 its chemical identity.
R = CH3 (alanine), CHCH3CH3 = Valine
4 main classes = polar (hydrophilic), non polar (hydrophobic), -ve, +ve charged.