1. UNIT 3 Genetics and Biotech
Bio 30 GB2 Investigate how genetic information is stored, transmitted and expressed at the molecular level.
Bio 30 GB1 Explore classical (i.e. Medelian) and current(i.e. chromosomal) understandings of biological inheritance.
Bio 30 GB3 Explore the impacts of historical, current and emerging biotechnologies on self, society and the environment.

2. DNA The Structure of DNA
– DNA image
The Structure of DNA

3. DNA Scientists who discovered the structure of DNA

4. Oswald Avery
Avery’s team determined that genes are composed of DNA

5. Erwin Chargaff
Chargaff discovered that DNA has the same amount of adenosine as thymine and the same amount of cytosine as guanine. A = T and G = C A T C G

6. Rosalind Franklin & Maurice Wilkins
Franklin and Wilkins used x-ray to discover that DNA was a double helix.

7. Watson and Crick
Watson & Crick won a Nobel Prize for discovering the structural model of DNA.
They credited Wilkins and Franklin. Wilkins also got a Nobel Prize but Franklin did not. Rosalind had passed away and the Nobels are not awarded posthumously.
1953

8. DNA is a Nucleic Acid
Nucleic acids are one of the major organic compounds.

9. Nucleic acids contain C, H, N, O, P Are made up of nucleotide monomers
sugar
phosphate
nitrogen base
Store genetic information
Help make proteins
Examples: DNA & RNA
NUCLEIC ACIDS
very large linear molecules
made up of nucleotides containing C, H, N, O, P
store genetic information, help to make proteins
examples: DNA and RNA
DeoxyriboNucleic Acid

10. DNA Structure phosphate nucleotide sugar nitrogen base PO4 N base PO4
The numbers are the positions of the carbons on the sugar.
(the 3’ end) 5 4 3 2 1
(the 5’ end)
PO4
N base
PO4
Sugar
N base
Sugar
DeoxyriboNucleic Acid

11. A NUCLEOTIDE 3. 1. 2. 3. 1. O 2. H3 P C H2 N H 1. Phosphate Group
2. 5-Carbon Sugar (Dexoyribose or Ribose) 1. 2. 3.
3. Nitrogen Base H H2 H3 O C N P 1. 2. 3.

12. A G T C Nucleotides Adenine Purines Guanine Thymine Pyrimidines
There are four nitrogen bases making up four different nucleotides. A
Adenine
Purines
Guanine G
N base T
Thymine
Pyrimidines
Cytosine C

13. Chargaff’s Base Pair Rules
Adenine always bonds with thymine.
Adenine (A) to Thymine (T) A T
The lines between the bases represent hydrogen bonds C G
Guanine always bonds with Cytosine.
Guanine (G) to Cytosine (C)

14. Pairing DNA Nucleotides
N-b
Nucleotide S C G
Rule A
Review slide. Make sure students can pick out the sugar, phosphate group, and nitrogen bases as well as know how the bases pair up (have them tell you the what the answers are before you animate it)
A to T A
C to G T G

15. 3’End
5’End
ladder shaped molecule
DNA DOUBLE HELIX

17. What is RNA? RNA stands for Ribo Nucleic Acid
RNA is DNA’s “helper” molecule.
sugar
phosphate
nitrogen base
RNA is a single stranded nucleic acid
Made up of monomers called nucleotides

18. RNA Nucleotides B A C A - Sugar (ribose) B - Phosphate
C - Nitrogen base
nitrogen base
sugar
phosphate B
Name the parts of the nucleotide.
RNA is made of nucleotide subunits arranged in a single strand
Ask students which molecules are which (before you animate the answers) A C

19. RNA Nitrogen Base Sugar (ribose) Phosphate Group
Identify the parts of the RNA strand.
Nitrogen Base
Make sure students know the molecules located in RNA. Have the students notice that RNA is single stranded whereas DNA is a double helix.
Sugar
(ribose)
Phosphate Group

20. Notice that RNA has Uracil (not thymine)
Rules for Base Pairing
Cytosine pairs with Guanine
C = G
Adenine pairs with Uracil
A = U
IMPORTANT!!!!!!!
Notice that RNA has Uracil (not thymine)

21. Rules for Base Pairing C = G A = U C G A U G C T A 3’ DNA strand
Teacher FYI – the transcription process moves from the 3’ end of DNA to the 5’ end and synthesizes an RNA strand of opposite polarity T A
RNA strand
5’ DNA strand

22. What is the function of RNA?
Carries DNA’s message code
Helps make protein
Types of RNA
Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)
Ask students the function of RNA; they should recall this from the organic molecules unit.
Introduce the three types of RNA; you don’t need to give their functions here.
Messenger (mRNA)
Transfer (tRNA)
Ribosomal (rRNA)

23. Comparing DNA & RNA DNA RNA √ √ √ √ Sugar is deoxyribose
Sugar is ribose
Adenine base is present
Cytosine base is present √ √ √
Review the differences between DNA & RNA
Have them tell you the answers to each before you animate the answers √

24. Comparing DNA & RNA DNA RNA √ √ √ √ Guanine base is present
Thymine base is present
Uracil base is present
Shape is double helix √ √ √
Review the differences between DNA & RNA
Have them tell you the answers to each before you animate the answers √

25. Comparing DNA & RNA DNA RNA √ √ √ √ Shape is single stranded
Located in nucleus
Located in cytoplasm
Stores genetic information √ √ √
Review the differences between DNA & RNA
Have them tell you the answers to each before you animate the answers √

26. Comparing DNA & RNA DNA RNA √ √ √ √ √ Functions in protein synthesis
Composed of nucleotides
Template for synthesis of proteins
Transcribes the Template
More than one type √ √ √
Review the differences between DNA & RNA
Have them tell you the answers to each before you animate the answers
You will probably have to tell them the answers to the 1st, 3rd & 4th question on this slide since they don’t know about protein synthesis yet; it will be a good review at the end of the chapter though. √ √

27. Video Nucleic Acids