1. SB2. The learner will analyze how biological traits are passed on to successive generations.
b. Explain the role of DNA in storing and transmitting cellular information

2. LEQ2:What is the role of DNA in storing and transmitting cellular information?

3. Try this……….
On a sheet of paper, draw a curving line that divides the paper into two halves.
Without tracing, copy the line on a second sheet of paper.
Hold the papers side by side, and compare the lines.
Do they look the same?
Now, stack the papers, one on top of the other, and hold the papers up to the light.
Are the lines the same?

4. THINK: How could you use the original paper to draw exact copies of the line without tracing it?
Why is it important that the copies of DNA that are given to new daughter cells be exact copies of the original?

5. Role of DNA Stores the code of life in a sequence of nucleotides.
The code is then used to make proteins and determine traits
The role of DNA is explained through the three processes included in the central dogma of biology.

6. Role of DNA Central Dogma of Biology
The central dogma includes three process.
Replication
Transcription
Translation
replication
transcription
translation

7. DNA Replication
DNA replication copies the genetic information of a cell
DNA replication is fast and accurate.

8. G2 checkpoint checks for errors in DNA replication
A single strand of DNA serves as a template for a new strand.
The rules of complementary base pairing direct replication
DNA is replicated during the S stage of the cell cycle
Each body cell gets a complete set of identical DNA
S (Synthesis) Stage
G2 checkpoint checks for errors in DNA replication

9. The DNA molecule unzips in both directions.
DNA Replication
DNA serves only as the template.
Enzymes and other proteins help carry out the process of replication (do the actual work of replication)
Enzymes unzip the double helix
Free-floating nucleotides form hydrogen bonds with the template strand.
nucleotide
The DNA molecule unzips in both directions.
DNA molecule unzips in both directions

10. DNA Replication
DNA polymerase enzymes bond the nucleotides together to form the double helix
DNA polymerase
new strand
nucleotide

11. DNA Replication
Two new molecules of DNA are formed, each with an original strand and a newly formed strand
DNA replication is semi-conservative
original strand
new strand
Two molecules of DNA

12. Concept Check
Describe the function of DNA replication and explain how cells help ensure that DNA replication is accurate?

13. Can you remember the 3 differences between DNA and RNA?
Transcription
Transcription converts a gene into a single stranded RNA molecule.
DNA RNA
Can you remember the 3 differences between DNA and RNA?

14. REVEIW RNA differs from DNA in three major ways: RNA has ribose sugar
RNA has uracil instead of thymine
RNA is a single stranded structure

15. Transcription
RNA carries the DNA’s instructions for protein synthesis.
The central dogma states that information flows in one direction from DNA to RNA to proteins.
RNA is the link between DNA and proteins.
replication
transcription
translation

16. Transcription Transcription make three types of RNA.
Messenger RNA (mRNA)
carries the message that will be translated to form a protein
Like the mailman
Ribosomal RNA (rRNA)
forms part of the ribosome where proteins are made
Transfer RNA (tRNA)
brings amino acids from the cytoplasm to ribosome.

17. Transcription Transcription is catalyzed by RNA polymerase
RNA polymerase helps recognize the start gene and unwinds a segment of DNA.
start site
nucleotides
transcription complex

18. Transcription Nucleotides pair with one strand of the DNA
RNA polymerase bonds the nucleotides together
The DNA helix winds back as the gene is transcribed.
DNA

19. Transcription
The RNA strand detaches from the DNA once the gene is transcribed.
RNA

20. Did you know… RNA can be found in your blood?
If forensic scientists find RNA, they can determine a time line of when a person was injured or killed.

21. Transcription
Trans.
Rep.
Complete the Venn Diagram below comparing and contrasting
Replication vs. Transcription:

22. Concept Check
If the DNA sequence had the nucleotides AGCCTA what would be the nucleotide sequence of the complementary DNA and the complementary RNA strand?
What process creates DNA?
What process creates RNA?

23. mRNA Protein Translation
Translation is the last processes involved in protein synthesis.
Translation converts an mRNA message into a protein, or polypeptide.
This process consists of three repeating steps.
mRNA Protein

24. Translation Amino acids are coded by mRNA base sequences.
Translation converts mRNA message into proteins by decoding the base sequence.
A codon (mRNA) is a sequence of three nucleotides that codes for a specific amino acid.
codon for
methionine
leucine

25. Translation
The genetic code matches each codon (mRNA) to its amino acid or function.
Three stop codons
UGA, UAA, UAG
One start codon, codes for methionine.
AUG

26. The genetic code matches each mRNA Codon with its amino acid or function

27. Translation
A change in the order in which codons (mRNA) are read changes the resulting protein.
Regardless of the organism, codons code for the same amino acids
Unity of life

28. Translation Amino acids are linked to become a protein or polypeptide.
An anticodon (tRNA) is a set of three nucleotides that is complementary to a codon (mRNA).
An anticodon is carried by a tRNA

29. Translation 3 Steps For translation to begin:
anticodon (tRNA) binds to its complementary start codon (mRNA) and signals the ribosome to assemble. The complementary tRNA bring its specific amino acid to the ribosome.

30. Translation
2. The ribosome helps form a polypeptide bond between the amino acids. The ribosome pulls the mRNA strand the length of one codon.

31. Translation
3. The now empty tRNA molecule exits the ribosome.The next complementary tRNA (anticodon) molecule binds to the next exposed mRNA (codon).
Processes are repeated for each codon (mRNA).
Once the stop codon is reached, the ribosome releases the protein and disables.

32. Concept Check
What would happen to the protein formed during translation if mRNA was copied incorrectly?

33. Put the following in order as they would occur in protein synthesis.
Concept Check
Put the following in order as they would occur in protein synthesis.
Transcription of mRNA in the nucleus of the cell.
The ribosome helps form a polypeptide bond between amino acids
The codon (mRNA) and the complementary anticodon (tRNA) bringing the specific amino acid to the ribosome.
The now empty tRNA leaves the ribosome and the process is repeated for each codon until the stop codon is reached.
The polypeptide is released from the ribosome

34. Proteins
Why do we need proteins?

35. Importance of Proteins
They are key to almost everything that living cells do
Transport materials
Fight off viruses/bacteria
Form muscles
Catalysts (enzymes)
speed up chemical reactions
Regulation of hormones
Communication between cells

36. Proteins All proteins are built from only 20 amino acids
Only 12 are made by the human body other 8 are found in certain foods
Essential Amino Acids (8)
Found in meat, eggs, cheese, soy products, and combinations of rice and beans

37. Did you know…
Proteins can be tested in a blood sample to find cancer in the body?
The picture shows a tumor in the lungs. Such a tumor can be found by looking for specific proteins.