1. Part II: Genetic Code and Translation
Protein Synthesis
Part II: Genetic Code and Translation

2. Which is single stranded?
DNA
RNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

3. Where in the cell does transcription take place?
Cytoplasm
Mitochondria
Nucleus
Golgi Body
Vacuole 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

4. If a DNA strand has the following sequence of base pairs – A C T G G T C C A A , then the mRNA strand would have what sequence?
T G A C C A G G T T
A C T G G T C C A A
T G U C C U G G T T
U G A C C A G G U U 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

5. mRNA is synthesized in the nucleus and travels to the cytoplasm to meet up with which organelle?
Mitochondria
Ribosome
Golgi Body
Lysosome
Nucleus 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

6. Genetic Code

7. Quick Review of Proteins…
Monomer: Amino Acid
20 different amino acids!
The properties of proteins are determined by the order of the amino acids

9. The Genetic Code! RNA contains 4 different bases: A, G, C, U
The genetic code is read three letters at a time
Each “word” of the coded message is three base pairs long
These “words” are called codons

10. Read sequence 3 bases at a time
RNA Sequence:
UCGCACGGU
Read sequence 3 bases at a time
UCG – CAC – GGU
Each set of three bases is a codon.
Each codon represents a different amino acid

12. …more genetic code AUG is the start codon
In addition there are 3 different stop codons.
Stop codons are like the period at the end of a sentence.

13. Using your mRNA codon chart, what amino acid would a ribosome call for if the codon was A A C ?
Phenylalanine
Glutamine
Asparagine
Lysine
Tyrosine 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

14. RNA and Ribosomes work together to produce proteins
Translation
RNA and Ribosomes work together to produce proteins

15. Transfer RNA For translation we need a new type of RNA
Transfer RNA (tRNA) is responsible for carrying different amino acids to the ribosome.
tRNA has a three base sequence called an anticodon

16. Steps in Translation mRNA attaches to the ribosome
tRNA brings in the amino acids
Anticodons match with codons
Peptide bonds form between amino acids

17. Translation Translation continues until a stop codon is read
The newly formed protein is released

18. Where in the cell does translation, the second part of protein synthesis, take place?
Mitochondria
Nucleus
Golgi body
Cytoplasm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

19. Molecules called tRNA’s are floating around the cytoplasm carrying what?
mRNA’s
Glucose
DNA
Nucleotides
Amino Acids 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

20. An mRNA codon is made up of how many nitrogen bases?1 3 6 24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

21. What protein would be synthesized from the following mRNA strand
What protein would be synthesized from the following mRNA strand? A C U U U C G A A U A C
Threonine – phenylalanine – glutamate – tyrosine
Phenylalanine – leucine – methionine – valine
Tyrosine – glutamate – phenylalanine – threonine
Threonine – cysteine – arginine – histidine 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30