4.2.5 Translation Flashcards
A gene is
a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein)
During transcription
DNA is transcribed and an mRNA molecule is produced
During translation
mRNA (messenger RNA) is translated and an amino acid sequence is produced
Translation occurs in
the cytoplasm of the cell
After leaving the nucleus, the mRNA molecule
attaches to a ribosome
In the cytoplasm, there are
free molecules of tRNA (transfer RNA)
These tRNA molecules have
a triplet of unpaired bases at one end (known as the anticodon) and a region where a specific amino acid can attach at the other
There are at least
20 different tRNA molecules, each with a specific anticodon and specific amino acid binding site
The tRNA molecules bind with their
specific amino acids (also in the cytoplasm)
The tRNA molecules bind with their specific amino acids (also in the cytoplasm) and bring them to
the mRNA molecule on the ribosome
The triplet of bases (anticodon) on each tRNA molecule pairs with
a complementary triplet (codon) on the mRNA molecule
Two
tRNA molecules fit onto the ribosome at any one time, bringing the amino acid they are each carrying side by side
A peptide bond is then
formed between the two amino acids
The formation of a peptide bond between amino acids requires
energy, in the form of ATP
The ATP needed for translation is provided by
the mitochondria within the cell
The translation stage of protein synthesis – tRNA molecules bind with their specific amino acids
