1. Ribosomes and Protein Synthesis
The Genetic Code
Proteins – long chains of _____________ (polypeptides) in a sequence specified by the genetic code
amino acids
The protein hemoglobin made of 4 polypeptide subunits

2. Ribosomes and Protein Synthesis
The Genetic Code 20
___ different amino acids create the polypeptide chains (a.k.a. proteins)

3. Ribosomes and Protein Synthesis
The Genetic Code
A sequence of __ letters on mRNA codes for ____ specific amino acid 3
one
3 letters is considered a "word"
_______ – a 3-letter word of mRNA coding for 1 amino acid
codon

4. Ribosomes and Protein Synthesis
The Genetic Code
64 ways that 4 letters can be combined into 3 codons
Note: most amino acids have more than one codon
AUG is methionine (met codon)…the “_______" codon of mRNA
start
There are 3 "stop" codons signal end of protein synthesis

5. ___________: the Process of Decoding mRNA into a Protein
Translation
To translate: changing from one language to another
In the cell, the nucleic acid is translated into a protein
I Want to Hold Your Hand
Komm, Gib Mir Deine Hand

6. Ribosomes and Protein Synthesis
Translation
Occurs on a __________ free in the cytoplasm or on a ribosome attached to the rough-ER
ribosome

7. Ribosomes and Protein Synthesis
Translation
Before translation, mRNA is transcribed in the nucleus and then moves to ___________
cytoplasm

8. Ribosomes and Protein Synthesis
Translation
mRNA attaches to ribosome
A specific amino acid is brought to the ribosome by a _______
tRNA
Each tRNA carries 1 specific amino acid
3 unpaired bases at bottom of tRNA (anticodon) are complementary to mRNA codon

9. Ribosomes and Protein Synthesis
Functions of the Ribosome
rRNA
(ribosome)
codon
mRNA

10. Ribosomes and Protein Synthesis
Functions of the Ribosome
Transfers amino acid from tRNA to growing polypeptide
1st codon

11. Ribosomes and Protein Synthesis
Functions of the Ribosome
1st codon
2nd codon

12. Ribosomes and Protein Synthesis
Functions of the Ribosome
2nd codon

13. Ribosomes and Protein Synthesis
Functions of the Ribosome
- Forms bond between new amino acid and previous one
- Breaks bond between new amino acid and tRNA that brought it in
- Moves down to next codon on mRNA
2nd codon
3rd codon

14. Ribosomes and Protein Synthesis
Functions of the Ribosome
- polypeptide grows by adding more _____________until stop codon is reached
amino acids
3rd codon

15. Ribosomes and Protein Synthesis
Functions of the Ribosome
3rd codon
4th codon

16. Ribosomes and Protein Synthesis
Functions of the Ribosome
4th codon

17. Ribosomes and Protein Synthesis
Functions of the Ribosome
4th codon
5th codon

18. Ribosomes and Protein Synthesis
Functions of the Ribosome
4th codon
5th codon

19. Ribosomes and Protein Synthesis
Functions of the Ribosome
5th codon
6th codon

20. Ribosomes and Protein Synthesis
Functions of the Ribosome
is a STOP codon
It causes the ribosome to release the amino acids and leave.
part of a protein
6th codon

21. Ribosomes and Protein Synthesis
Molecular Basis of Heredity
Information is transferred from DNA  RNA  proteins (a few exceptions…virus)
DNA
mRNA
tRNA
rRNA
(ribosome)
blueprint
codon
mRNA
foreman
supplies
carpenters

22. Ribosomes and Protein Synthesis
Molecular Basis of Heredity
Genes make proteins; proteins build body or operate cells