1. Bio 211
d16 DNA!

2. Some questions
What determines traits Mendel studied or that we looked at in fly or cat lab? (flower or eye color, hair length or texture)
How do we know DNA is responsible?
What is DNA the code for?
What is DNA made of? What is protein made of?
How does DNA code for protein?

3. Short group exercise
Draw sugar-phosphate-base structure of double stranded DNA with the following sequence:
5’ – ATGCCCTGA – 3’
NOTES: show it is antiparallel and complementary

4. DNA size and units Measured in base pairs
3bp – codon; information for one amino acid
1kb – 1000bp, an average gene (~333 aa)
1Mb – 1000kb, a million bp
OUR genome: 3 billion bp; 3000 Mb
(2 meters long; nucleus is 6um)
E coli genome: 4.6 Mb
(3mm; 2um bacterium)

5. Eukaryotic DNA packaging eg
Eukaryotic DNA packaging eg. human: 2m DNA  6 uM nucleus; multiple condensed chromosomes

6. DNA replication

7. PCR POLYMERASE CHAIN REACTION Amplify a small portion of the DNA Why?
Enough DNA of a known gene to sequence from a crime scene or an unknown bacterium or to do a paternity test

8. How does PCR work? One thing about DNA replication
DNA polymerase cannot START a DNA chain – it needs PRIMERS – short chains of AGCTs to which DNA polymerase can add more AGCTs
In the cell this is done by the enzyme PRIMASE

9. How does PCR work? What do we need to make a piece of DNA? DNA
DNA polymerase
Primers
Individual nucleotides (A, G, C and Ts)
BUT WAIT – how do we TARGET the DNA we want to amplify?

10. PCR lab PTC – phenithiocarbamide bitter taste receptor
SNP – single nucleotide polymorphism (we have 2 alleles that differ by only one letter)
Ability to taste is dominant over inability
Use PCR to determine your GENOTYPE
First predict and then test your PHENOTYPE
Compare – does it make sense?

11. Go to part b

12. Fun facts

13. DNA size and units Measured in base pairs
3bp – codon; information for one amino acid
1kb – 1000bp, an average gene (~333 aa)
1Mb – 1000kb, a million bp
OUR genome: 3 billion bp; 3000 Mb
(2 meters long; nucleus is 6um)
E coli genome: 4.6 Mb
(3mm; 2um bacterium)

14. Eukaryotic DNA packaging eg
Eukaryotic DNA packaging eg. human: 2m DNA  6 uM nucleus; multiple condensed chromosomes

18. Short group exercise
Draw sugar-phosphate-base structure of double stranded DNA with the following sequence:
5’ – ATGCCCTGA – 3’
NOTES: show it is antiparallel and complementary

19. Now let’s copy it Draw the two strands again Pull them apart
Copy them each letter by letter
End up with two identical DNAs

25. DNA replication

26. PCR POLYMERASE CHAIN REACTION Amplify a portion of the DNA Why?
Enough DNA of a known gene to sequence from a crime scene or an unknown bacterium or to do a paternity test

27. But first… One thing about DNA replication
DNA polymerase cannot START a DNA chain – it needs PRIMERS – short chains of AGCTs to which DNA polymerase can add more AGCTs
In the cell this is done by the enzyme PRIMASE

28. How does PCR work? What do we need to make a DNA?
Something to copy: DNA
Something to do the copying: DNA polymerase
Something to start the chain: Primers
Something to make the chain with: Individual nucleotides (A, G, C and Ts)
BUT WAIT – how do we TARGET the DNA we want to amplify?
PRIMERS!!

29. PCR preview video

30. PCR lab PTC – phenithiocarbamide bitter taste receptor
SNP – single nucleotide polymorphism (we have 2 alleles that differ by only one letter)
Ability to taste is dominant over inability
Use PCR to determine your GENOTYPE
First predict and then test your PHENOTYPE
Compare – does it make sense?