Protein Synthesis(Translation)

Pre-AP BiologySeptember 30, 2020

Goal: I will understand the steps of protein synthesis, focusing on step 3 –translation, and how to use the mRNA strand to build the protein one

amino acid at a time.

Protein Synthesis has Three Steps:

1. DNA Replication (Monday)

2. Transcription – producing mRNA (Tuesday)

3. Translation – making protein (today)*

STEP 2 STEP 3STEP 1

Anticodon

: Put a line after every 3rd letter so that it is easier to see the codons!

: Put a line after every 3rd letter so that it is easier to see the codons!

The final step in protein synthesis Step 3. Translation is when the cell uses the information

on the mRNA strand to build the protein

Ribosomes are composed of a large and small

subunit, each of which contains its own rRNA

molecules to help “read” or decode the mRNA strand

and build the protein

Ribosomal RNA (rRNA) associates with a set of

proteins to form ribosomes

During the construction of a protein, the mRNA attaches to the ribosome at the start codon (AUG)

A third type of RNA called transfer RNA (tRNA) brings the proper amino acid according to the sequence in the mRNA strand

and is the base pair (compliment) of the

mRNA codonChecking system!

Each type of tRNA carries only one

kind of amino acid

The code on the bottom of each

tRNA is called the anticodon

The ribosome attaches the next amino acid into a chain that grows into

a polypeptide

When the ribosome reaches a stop codon (UAA, UGA, UAG) it

releases the newly formed polypeptide which foldsinto a protein (type of

protein folding will determine its function)

This completes the process of protein

synthesis! J