DNA Translation - Making Proteins

Question 1

Why does Translation happen?

Answer 1

For a cell to create the proteins it needs

Question 2

What happens in Translation?

Answer 2

For a cell to create the proteins it needs, it must translate the codons along a stretch of mRNA into amino acids sequences
Once the mRNA reaches the cytoplasm, the translator and proteins synthesis equipment work together to assemble the proteins
The molecule that links each mRNA codon to it specific amino acid is another form of RNA called transfer RNA (tRNA)
Single stranded
Contains the anti-codon – a stretch of three nucleotides that is complementary to the mRNA codon
At the opposite end is a binding side for the amino acid that responds to the codon

Question 3

How do the ribosomes help? - the site of protein synthesis

Answer 3

The ribosomes brings together the mRNA strand, the tRNA molecules, and the enzymes needed to build the polypeptides
They also contain a third kind of RNA known as Ribosomal RNA (rRNA)
Translation is activated when an mRNA molecule binds to a ribo. complex and exposes two adjacent codons
The 1st codon (a start codon AUG) base pairs with tRNA carrying the amino acid methionine
Then translation can begin
Another tRNA molecule (carrying an amino acid) arrives at the adjacent codon
Enzymes will join the aa carried by the first tRNA to the aa carried by the second tRNA
The ribosome moves to the adjacent codon along the mRNA strand
The first tRNA molecule can then detach from the mRNA and pick up another aa
The second tRNA molecule now holds a growing aa chain
A third tRNA molecule arrives at the newly exposed codon next to the second tRNA and the cycle repeats until a stop codon is reached

Question 4

Termination in Translation

Answer 4

The mRNA stops codons tell the ribosomes that the polypeptide chain is done
An enzyme called a release factor allows the ribosome to let the mRNA and polypeptide chain go
The resulting protein goes to do it’s job in the cell (ie. Hair, skin, muscle etc)