Translation:mRNA to protein

How is DNA used to make proteins?DNA mRNA Protein

Transcription Translation

DNA mRNA Protein

Processing Piece:

1) What are the building blocks of proteins?2) A polypeptide chain is a chain of ______________.

What is translation?When mRNA is used to make protein.

Where does translation happen? At the ribosome

Processing Piece:

• Draw a picture to help yourself remember the definition of translation.

(Example: A waitress takes the order to the kitchen where it is used to make the food.)

What is a codon? • 3 bases (“letters”) of a DNA or mRNA sequence. Example: CAG• Each codon is the instructions for one amino acid.

What is an anticodon?• 3 bases (“letters”) that will pair up with a codon.• Found on tRNA

Processing Piece:2) If the bases on a codon are UGC, what will the bases on the anticodon be?

3) If the bases on a codon are GCU, what will the bases on the anticodon be?

What is tRNA?• A small, folded piece of RNA that has an anticodon

on one side and an amino acid on the other side

What are the steps of translation?1) The mRNA transcript goes to the ribosome,

and the ribosome holds it in place. One of the codons on the mRNA is in the middle of the ribosome.

2) A tRNA molecule pairs up with the codon that’s in the middle of the ribosome; if the anticodon on the tRNA matches with the codon on the mRNA, the tRNA will attach to the mRNA.

Processing Piece:

• Illustrate the first 2 steps of translation.

What are the steps of translation?3) Another tRNA pairs with the next codon, and the 2 amino acids are joined together. 4) One by one, all the codons are translated into amino acids until the ribosome reaches the stop codon, resulting in a polypeptide chain (a chain of amino acids) which is folded together to make a protein.

Processing Piece:

• Illustrate the last 2 steps of translation.

What is a start codon?• A codon (AUG) that tells the ribosome “start

translating here;” it will be translated into the first amino acid (methionine).

What is a stop codon?• A codon (UAA or UAG) that tells the ribosome “stop

translating here.”

Processing Piece:

Draw a picture of a gene. Show where you would find the start codon and the stop codon.

What is a codon chart?• A chart that tells you what amino acid will come

from a codon on the mRNA when it is translated.

What is a codon chart?• Example: If the mRNA is UAU, the amino acid will be

__________________________________.

What is a codon chart?• Example: If the mRNA is UAU, the amino acid will be

tyrosine.

Circle each codon in the following nucleotide sequences, then count how many there are.

1) AUG CAC CGU UAA CUA How many codons are there? ______

Circle each codon in the following nucleotide sequences, then count how many there are.

2) AUGCCUAUAGAC How many codons are there? ______

Use your codon chart to translate each of these mRNA transcripts into amino acids:

5) mRNA sequence: AUG UCA ACG UCA ACU amino acid sequence: ___________________

Use your codon chart to translate each of these mRNA transcripts into amino acids:

6) mRNA sequence: AUGCCGUAUAGA amino acid sequence: ___________________

8) DNA nucleotide sequence: TAC GAT AAT CGA CGA TTA ATC

mRNA nucleotide sequence: ___________________________

amino acid: ______________________________________

9) DNA nucleotide sequence: TAC GAT GAA ATC AAT TCA

mRNA nucleotide sequence: ___________________________

amino acid: ______________________________________