1. Please take out your lab book and prepare for a warm-up!
Inquiry 1/8 and 1/11
Please take out your lab book and prepare for a warm-up!

2. Warm-Up 1/18 & 1/11
How are the words below related? You can draw a diagram, concept map, or write sentences
DNA Amino Acids Proteins
Enzymes

3. Warm-Up Answer DNA provides the directions/code to make proteins
Proteins are made of amino acids
Enzymes are the most important type of protein- they build and break down molecules in your body

4. DNA Extraction Lab Review the flowchart procedure you drew last time
Extract DNA from both strawberries and peas
Answer the analysis questions in your lab book (under the flow chart)

5. Clean Up Time
Wash all glassware and leave your station looking exactly as you found it
Restock cheesecloth and Ziploc bags (two per station)- extras are on the black cart

6. DNA Basics

7. DNA’s Job
DNA carries information from one generation to the next (parent to child)
Every cell in your body has the same 46 chromosomes of DNA
DNA determines how you look by making proteins
Most of these proteins are enzymes, which are the tools that build your body

8. Structure of DNA Long molecule made of nucleotides
Every nucleotide has three parts:
5 carbon sugar
Phosphate group
Base (contains Nitrogen)

9. Structure of DNA Nucleotides link to form strands of DNA
Nucleotides have the same sugar and phosphate
There are four different bases: adenine (A), guanine (G), cytosine (C), thymine (T)

10. Nucleotide Practice
Phosphate
Following this example, draw the four different types of nucleotides found in DNA
Adenine (A)
Sugar

11. How do Nucleotides Fit Together?
Sugar and phosphate make up the backbone; bases are protected in the middle
DNA strands have a 5’ end, which starts with a phosphate, and a 3’ end, which ends with a sugar
DNA is always built in the 5’ to 3’ direction!

12. How Bases Pair Up A and T always pair up; G and C always pair up
Chargaff’s Rule:
The percentages of A and T are the same within a DNA molecule; so are G and C!
All organisms follow this rule:
[A] = [T] and [G] = [C]

13. Percentage of Bases in Organisms
Streptococcus
29.8
31.6
20.5
18.0
Yeast
31.3
32.9
18.7
17.1
Herring
27.8
27.5
22.2
22.6
Human
30.9
29.4
19.9
19.8

14. The Double Helix DNA is made of two complementary strands
The strands are wound in a double helix
The strands are held together by hydrogen bonds
Hydrogen bonds result from attractions between H, N, and O on the bases

15. The Double Helix

16. DNA Pioneers
James Watson (US) and Francis Crick (UK) created the first model of the double helix in 1953
They deduced the structure using information from Rosalind Franklin, who created an x-ray photograph of it
Franklin passed away before receiving the Nobel Prize, but it was awarded to Watson and Crick

17. two nucleotides for you!
Self Test!!!
Draw one strand of DNA with the sequence AGTACG. Then, draw in the other strand, pairing A with T and G with C
I drew the first
two nucleotides for you!

18. It looked just like this, right?
Now label the 5’ and 3’ ends of each strand!

19. DNA Modeling Activity Today’s Big Steps:
In pairs, select a DNA sequence
Build your DNA molecule by cutting and pasting nucleotides
One person cuts, one glues
Color/shade G = yellow, T = pink,
A = green, C = blue
Do Analysis Questions

20. Due Dates
Monday, 1/11: Genetics retakes, corrections, and sugar/cancer rdg. Due
(you did either corrections OR the reading)
Tuesday, 1/12: Strawberry lab due