1. Warm-UP
Name the enzyme that breaks the Hydrogen bonds between the nitrogen bases during DNA Replication.
Name the enzyme that proofreads the newly made complimentary DNA strand.
List 4 conclusions drawn by Watson and Crick
Which scientist was responsible for developing ‘Photo 51’?
What does Charguff’s Rule state?

2. Make a complementary DNA strand
Parent DNA strand: GCATTAGCCTAGGC

5. PROTEIN SYNTHESIS: DNA Transcription and Translation

6. Essential Review
What are the four macromolecules organisms are made of?
Which one is used mostly for structure?
What is the monomer (-o-) of this macromolecule ( o-o-o- o) ?
What do proteins have to do with the genetic traits?

7. DNA can NOT leave the nucleus. “Big Boss”
Molecular Genetics
DNA, RNA, and Protein
DNA  RNA Protein
DNA can NOT leave the nucleus. “Big Boss”
So, how does the info from DNA get to the cytoplasm (ribosome)?

8. Amoeba Sisters Protein synthesis (8:46)

9. Ribonucleic Acid (RNA)
Macromolecule that makes RNA is nucleic acid
Monomer: nucleotides (like DNA).
Recall: nucleotides are made of a sugar, phosphate, and nitrogen base.

10. DNA vs. RNA DNA is double stranded, and RNA is single stranded.
This means that RNA is SMALLER than DNA, so it can leave the nucleus.

11. DNA vs. RNA
RNA contains 4 nitrogen bases: adenine, guanine, cytosine and URACIL.
Uracil bonds to adenine in RNA. It essentially takes the place of thymine.
Thymine is NOT
present in RNA.

12. DNA vs. RNA
RNA contains the 5-carbon sugar ribose. (Recall DNA contains deoxyribose).
Ribose has one more oxygen atom than deoxyribose.
Ribose Deoxyribose

14. 3 Types of RNA
RNA’s job is to help DNA make proteins (protein synthesis).
DNA must deliver its code to the remainder of the cell- it relies on 3 molecules:
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)

15. mRNA, rRNA, tRNA

16. Messenger RNA (mRNA)
Messenger RNA (mRNA): form of RNA that carries genetic information from DNA as a sequence of bases inside the nucleus to the ribosomes present inside the cytoplasm.
mRNA serves as a template for protein synthesis.

17. Ribosomal RNA (rRNA)
Ribosomal RNA (rRNA): a major component of ribosome that guides the translation of mRNA into a protein.
rRNA helps bind amino acids together to make polypeptides (proteins).
rRNA is found outside of the nucleus.

18. Transfer RNA (tRNA)
Transfer RNA (tRNA): form of RNA that brings amino acids to ribosomes during protein synthesis.
tRNA is found outside of the nucleus.

19. 12.3 DNA, RNA, and Protein Chapter 12 Molecular Genetics
CODON [ ] Anticodon

20. Bring amino acids to ribosome
RNA Concept Map
Section 12-3
RNA
can be
Messenger RNA
Ribosomal RNA
Transfer RNA
also called
which functions to
also called
which functions to
also called
which functions to
mRNA (Codon)
Carry instructions
rRNA
Combine
with proteins
tRNA (anticodon)
Bring amino acids to ribosome
from to
to make up
DNA
Ribosome
Ribosomes
Go to Section:

21. Central Dogma Defined by Francis Crick
The central dogma states that the information flows in one direction from DNA to RNA to proteins:
DNA → RNA → protein.

22. Transcription Transcription is the first part of protein synthesis.
During transcription, mRNA is created by transcribing the DNA’s code.
Transcription occurs inside the nucleus

23. Transcription
1. During transcription, the enzyme RNA polymerase temporarily unzips DNA and adds RNA nucleotides to the growing mRNA strand.

24. Transcription
2. Once the mRNA strand is completed, it leaves the nucleus (exits via nuclear pores).
3. mRNA travels to a ribosome and delivers the DNA message/instruction for making proteins.

25. DNA Transcription and Translation

26. Transcription Practice
Transcribe the following DNA sequence into a complimentary mRNA sequence DNA template strand: TAACGCATA Complimentary DNA strand: mRNA strand:

27. Information Flow: DNA to RNA to Protein

28. Intro. to Translation
1. Translation is the final step of protein synthesis- it involves ALL THREE types of RNA (mRNA, rRNA and tRNA). 2. Translation is a process in which the mRNA that was manufactured during transcription is translated into an amino acid sequence (protein). 3. Occurs in the cytoplasm, on the ribosomes

29. Translation Ribosome “reads” the messenger RNA (mRNA) codons.
Codon: a three-nucleotide sequence that codes for a specific amino acid.
1 codon = 1 amino acid

30. Transfer RNA has anticodon

32. Translation
1. The mRNA made as a result of Transcription attaches the rRNA at start codon, AUG . 2. tRNA arrives site with specific anticodon and amino acid.

34. Translation
3. Amino acid from and rRNA moves one codon. 4. The process is repeated and the amino acid chain elongates till stop codon is reached. 5. No corresponding tRNA is found, so the entire complex dissociates and protein is made.