1. Notes pg. 77: Protein Synthesis (WS)
EQ1: How are proteins made?
EQ2: What is RNA?
Week 17

2. Protein Synthesis
Process by which an organism’s genotype is translated into its phenotype. EX: Genotype: Bb, Phenotype: Brown Eyes
Genes code for amino acids that make up proteins
DNA is the template or pattern for making proteins. Like a blueprint or recipe!

3. If you had the only copy of a secret family recipe that you wanted to share with your brother, would it be better to:
Take the priceless recipe to his house and risk losing it or wrecking it
Make him a copy/Send him a picture of the recipe while the original stays safe and sound at home

5. DNA → RNA → Protein
RNA is only single-stranded (1-sided) NOT a double helix.

6. DNA and RNA work together!
They have to work together to make proteins.
DNA (Deoxyribonucleic acid)
RNA (Ribonucleic acid)
3 Kinds of RNA
mRNA (messenger)
tRNA (transfer)
rRNA (ribosomal)

8. Protein Synthesis: 2 Stages
First Stage:
Transcription: genetic information from a strand of DNA is copied into a strand of mRNA.
“Transcribe” means to copy

9. Q Left Student: What 4 bases is DNA made of?
Think-Pair-Share
Q Left Student: What 4 bases is DNA made of?
Q Right Student: How do the 4 bases pair up?

10. A T C G A T G C C G

11. Transcription RNA Bases: DNA Bases:
Adenine to Uracil
Guanine to Cytosine
DNA Bases:
Adenine to Thymine
Begins with DNA Helicase (enzyme) that unzips the DNA so that now unattached RNA can pair up to the open strand of DNA.
Then RNA polymerase builds the mRNA.

13. Practice Together!
Transcribe (Copy DNA to RNA) the following sequences at the bottom of your notes:
TGCAGTTCA
TAGCGAATCGTA
GATGCACTGTACTGG
Remember:
C still goes with G
G still goes with C
T still goes with A
But for RNA:
A now goes with U
*Everywhere you would put a T during replication, now put a U for transcription!*

14. DNA Transcription Practice ½ sheet! page 78

15. DNA
Helicase

16. WEDNESDAY

17. DNA Translation into mRNA

18. Second Stage: Translation
Back of Notes WS
Second Stage: Translation
Translation: “language” of nucleic acid (RNA bases) is changed into the “language” of protein (amino acids).

19. Building Proteins Translation (2nd Stage)
mRNA carries or moves genetic information out of nucleus and then the information gets translated to form proteins. Process involves linking amino acids together.
tRNA transfers amino acids to the ribosomes. (Main JOB is to transport amino acids).

20. Introns & Exons
Introns are regions of DNA that do NOT code for proteins.
Exons are regions of DNA that DO code for proteins.
The non-coding introns are removed (cut out) of the copied mRNA strand before leaving the nucleus. When done, the mRNA leaves the nucleus and goes to the ribosome in the cytoplasm.

21. Codons Anticodons are 3 bases found on tRNA.
tRNA carries only one anticodon.
tRNA anticodon complements a specific mRNA codon.
tRNA = AGU
mRNA = UCA
They fit like puzzle pieces.
Codons are a 3 base section of mRNA. They carry for a specific amino acid.
GCU codes for the amino acid Alanine
mRNA carries many codons

24. Start and Stop Codons Signal a ribosome to start and stop translation.
They are found at the beginning and end of a mRNA code.
Universal Start Codon = AUG (methionine)
Universal Stop Codons = UAA, UAG, and UGA

25. Stage 1
Stage 2
Protein

26. DNA vs. RNA Video
2 facts: page 77

27. Transcription of mRNA into a Protein

29. Protein synthesis: The whole process:
Stage 1 Transcription (make mRNA)
&
Stage 2 Translation (make proteins using tRNA)

30. WEDNESDAY: CODON PRACTICE

31. DNA Codon Table Practice Sheet: page 79

32. The 20 AAs & their codons
(Chart on book page ___) Will be given for final but you must know how to use it!

33. Back of Codon WS: page 79