Download Protein Synthesis

Steps in Protein Synthesis
Step 1: Transcription
Location: nucleus
Purpose: to copy the DNA code (order of bases) into mRNA.
Events:
1.) DNA is unwound and DNA Helicase unzips DNA
strand.
2.) RNA Polymerase reads the complementary base
and adds free RNA nucleotides to fill in the empty
spaces along the side of DNA.
3.) mRNA is made, leaves the nucleus to go to ribosome.
Step 2: Translation
Location: in the cytoplasm, on the ribosome
Purpose: to convert the instructions of RNA
(order of bases) into amino acids, this will
make up the protein.
Events of translation:
1.) The first three bases of mRNA (codon)
join the ribosome. AUG – is the start
codon
2.) tRNA brings the amino acid down to the
ribosome. The three bases on tRNA, or
the anticodon, match the complementary bases on mRNA.
3.) Each tRNA has an amino acid attached to it which is determined by its anticodon.
Ex: codon (AUG) Amino Acid - methionine
4.) The amino acids are joined by polypeptide bonds.
5.) The resulting chain of amino acids are called a PROTEIN.
Codons & Anticodons
Definition: three nucleotides of mRNA.
Start codon: AUG; starts protein synthesis
Stop Codons: UAA, UAG, UGA; stops protein
synthesis
Amino Acids
 Definition: they are the building blocks of proteins
 There are 20 essential amino acids
 Protein = AA chain OR = polypeptide chain
The order of AAs determine the function of the protein!!!
1. DNA
2. mRNA
3. nucleus
5. rRNA (ribosome)
6. Codon
7. anticodon
9. Amino acid
10. protein
4. cytoplasm
8. tRNA