2. WORK PLAN
• Recall of terms
• Code Breaking Activity
• What is Protein Synthesis
• What are the steps of protein
synthesis
• Protein Synthesis Challenge
• Wrap up
• Agreement
3. What we already know about DNA
• The nucleus of the cell
contains DNA
• Genes are specific sections
of DNA
• DNA – deoxyribonucleic acid
• The DNA molecule is a
double helix (shaped like a
twisted ladder)
• The DNA subunits are:
Phosphate, Sugar, and
Nitrogen base
4. What we know about the genetic
code
• There are four DNA bases:
Adenine, Thymine, Cytosine,
Guanine
• The DNA bases compliment
each other: A-T & C-G
• Three bases codes for one
amino acid (triplet code)
• A gene is the entire
sequence of bases that
codes for a specific protein
5. What we know about RNA
• RNA – ribonucleic acid
• RNA has a ribose sugar
instead of deoxyribose
sugar
• RNA has Uracil instead of
Thymine
• RNA is a single strand
6. What we know about proteins
• Proteins are large molecules made up of
amino acids
• Different combinations of amino acids form
different proteins
• Protein is a component of
enzymes, hormones, and muscles
7. Code Breaker
• Decode the message hidden in the words
• Clue: CAPITAL
Life Overcomes Nothing Greater Than Itself
Minus Everything. Now Only Seems Extremely
Easy. Jumping Under Something
Terrible, Another Quirkily Useless Idiot Crafted
Knives. Verily It Stayed In There To Hurt
Openly Unique Goat Herders.
8. Code Breaker
• Answer:
Long time, no see. Just a quick visit, though
9. Code Breaker
• Use the cipher to figure out the message
10. Code Breaker
• Answer:
Those who know the enemy as well as they
know themselves will never suffer defeat.
~ Sun Tzu ‘Art of War’
11. BIG IDEA
Breaking the code
Cells transcribe and translate
codes to make protein
13. What is protein synthesis?
• Protein synthesis is the
process of making proteins
using the genetic code found
in DNA
• It involves two processes:
• Transcription
• Translation
DNA RNA Protein
14. Quick Check
• What is protein synthesis?
• What are the processes involved in protein
synthesis?
15. Transcription
• Uses one strand of DNA as
a pattern or template
• It produces a single-
stranded mRNA molecule
• It happens inside the
nucleus
16. Steps of Transcription
1. The DNA molecule
opens up along the
gene
2. RNA nucleotides (A, U,
C, G) match up and join
the open DNA strand
3. The complete RNA
strand (mRNA) is
released an moves out
to the cytoplasm
17. Difference of Translation to
Replication
• Only one strand of DNA is transcribes, so
only one strand of mRNA is produced
• The mRNA is released, it does not stay
attached to the DNA
• Many copied of mRNA can be made from a
single gene in a short period of time
18. Quick Check
• What are the steps of transcription?
• How is transcription different to replication?
19. Translation
• Translation is how the cells
relate the code of nucleotide
bases to the language of
amino acids.
• Translation occurs in the
cytoplasm, specifically at
ribosomes
• The ribosomes use mRNA
and tRNA to make proteins
20. Steps of Translation
1. The mRNA attaches to a
part of the ribosome.
2. tRNA that carries amino
acids will match the
triplet codes of the
mRNA
3. The amino acid chain
becomes longer as more
tRNA matches up with
mRNA
22. Steps of Translation in Detail
1. Translation begins when a ribosome attaches to the
beginning of an mRNA molecule
2. A tRNA molecule carrying an amino acid matches up
to a complementary triplet on mRNA on the ribosome
3. The ribosome attaches one amino acid to another as
it moves along the mRNA molecule
4.The tRNA molecules are released after the amino
acids they carry are attached to the growing chain of
amino acids
5. The ribosome completes the translation when it
reaches the end of the mRNA strand and the newly
made protein molecule is released
23. Quick Check
• Where does translation occur?
• Which RNA does the actual translation of
bases into amino acids?
24. Summary
• mRNA is transcribed from DNA in the nucleus
• tRNA translates mRNA into amino acids by
matching nucleotide bases codes
• Ribosomes connect the amino acids together
to form protein
• Check this link to see a video summary:
http://www.youtube.com/watch?v=NJxobgkPEAo
25. Protein Synthesis Challenge
• Copy this DNA sequence:
A–T–G–A–C–G
• Write the base pairs of the complimentary strand of
DNA (replication)
• Write the complimentary mRNA strand to your new
strand (transcription)
• Use the chart to find the correct amino acid s that the
tRNA would attach to the protein chain (translation
28. Answers
• Replication
T–A–C–T–G–C
• Transcription (mRNA)
A–U–G–A–C–G
• Translation (amino acids)
Met (Methionine) and Thr (Threonine)
29. Agreement
• Bring the following materials for the GRASPS
activity next meeting:
• Coloring materials
• Letter-sized papers (white or colored)
• Pencil
• Scrap book materials and/or old colored
magazines
• Scissors
• Glue
30. Resources
• Lam Peng Kwan, Eric Y K Lam, Biology Matters
GCE O Level, Marshall Cavendish Education
• http://www.slideshare.net/MrsTabor/dna-for-7th-
grade#btnNext- Tan, Angeline (2010). Science
Process Skills.
• http://ims.ode.state.oh.us/ODE/IMS/Lessons/Conte
nt/CSC_LP_S02_BC_L10_I05_01.pdf
• http://www.youtube.com/watch?v=NJxobgkPEAo
