GETTING TO KNOW DNA:

1. GETTING TO KNOW DNA:

2. Below is one of the molecules that makes up DNA. What functional groups do you see in the molecule: • Hydroxyl • Carboxyl • Amino • Phosphate

3. As you know, DNA stands for…. DEOXYRIBONUCLEIC ACID

4. Is DNA a monomer or polymer • Monomer • Polymer

5. What does it mean to be a monomer? What does it mean to be a polymer???

6. If we were reviewing proteins, the monomer units would be: • Nucleic acids • Fatty acids • Sugars • Amino acids

7. The monomer units of DNA are known as…. NUCLEOTIDES

8. One of FOUR different NITROGEN BASES Phosphate Group Sugar= Deoxyribose All nucleotides have three “parts” in common. They all contain….

9. PHOSPHATE NITROGEN BASE SUGAR We will use our hands to represent a nucleotide.

10. A T G C The four different Nitrogen Bases for DNA are abbreviated using the following letters…. Adenine Thymine Guanine Cytosine

11. Using your two hands, please show how you think two nucleotides will/should bond together. Did you put your hands like this???

12. Time to find out why this is wrong!!!

13. LOOK! TWO RINGS!!! Adenine and Guanine are larger molecules known as… PURINES

14. LOOK! Only one ring!! THYMINE and CYTOSINE are smaller molecules known as… PYRIMIDINES

15. Full Finger Half Finger Now, when using our hands to represent the nucleotides, we must modify the nitrogen base in order to represent these PURINES and PYRIMIDINES. How would you represent a large PURINE? How would you represent a small PYRIMIDINE?

16. In DNA, a PURINE always bonds with a PYRIMIDINE when forming a “rung” of the DNA ladder. LOOK! A long finger pairs with a short finger! In other words, a purine pairs with a pyrimidine.

17. T A In DNA, Adenine always pairs with Thymine using two hydrogen bonds.

18. C G In DNA GUANINE always pairs with CYTOSINE using three hydrogen bonds.

19. Time to use your brain and hands in order to review nucleotide structure and type. USING YOUR HAND, SHOW ME THYMINE USING YOUR HAND SHOW ME ADENINE SHOW ME CYTOSINE SHOW ME HOW CYTOSINE AND THYMINE BOND TO FORM A RUNG ON THE LADDER THEY DON’T

20. OK Now that you recognize nucleotide type and structure, it’s time to start building the polymer from these monomers.

21. The molecules marked “W” are best described as: • Monomers • Polymers • Isomers • isotopes

22. Reactions A and B are respectively known as: • Dehydration, hydrolysis • Condensation, hydrolysis • Polymerization, decomposition • Hydrolysis, dehydration A B

23. Molecule(s) “X” are most likely: • Carbohydrates • Monomers • Polymers • Water • Starch

24. If molecule “W” is a nucleotide, molecule marked “Y” is most likely: • Protein • Starch • DNA • Galactose • Fructose

25. Look. Many Rungs. Etc… In order to make a molecule of DNA, you would need to create many rungs to the DNA ladder.

26. Sugar, Phosphate. Sugar, Phosphate. Sugar, Phosphate. Etc… What part of the nucleotide alternates to form the sides of the DNA ladder? Etc…

27. The Nitrogen Bases What makes up the “RUNGS” of the ladder?

28. Go Ahead! Stack you hand on top of your partners hands building two rungs of the DNA ladder.

29. Why is this WRONG????

30. The sides of the DNA ladder “run” in opposite directions. One side is actually flipped and the nucleotides are upside down!

31. TRY IT!!!

32. Because the sides of the DNA “run” in opposite directions, DNA is said to be ANTIPARALLEL.

33. 5 prime 5 prime In this DNA molecule, the THUMB part or better known as the PHOSPHATE GROUP, is said to be the 5 prime (5’) end.

34. 3 Prime 3 Prime The “hand” or sugar part of the DNA molecule makes up the 3 prime (3’) end of the DNA ladder.

35. If you link enough nucleotides together, the DNA molecule begins to take on the characteristic shape known as the Double Helix

36. Let’s Build Some DNA!!

37. You Need… • Two Pipe cleaners • Two red twizzlers • Two black twizzlers • Many toothpicks • Four different colored marshmallows

38. The marshmallows represent the nitrogen bases. Let’s decide as a class what colors will represent the following nitrogen bases. ADENINE= CYTOSINE= GUANINE= THYMINE=

39. Person One Cut the black twizzlers into 1.5 cm pieces. These will represent the phosphate groups Person Two Cut the red twizzlers into 3 cm pieces. These will represent the sugars.

40. Add the twizzlers to the pipe cleaners. Remember, you need to alternate SUGAR (red) AND PHOSPHATE GROUPS (black). When you are finished, your strand should not end in the same color you started with!

41. Did you and your partner make the same number of nucleotides on the sides of your ladder? If not, FIX IT!!!

42. Time to put together the two sides. Using the toothpicks and marshmallows, you are to add the nitrogen bases to the sides of the ladder. Remember, the nitrogen bases “come off” the sugar part of the nucleotide. As a result, they should be coming off of the red twizzler. Please use two of the same color marshmallows to represent one ADENINE and GUANINE. The BIG purines. Please use only one marshmallow to represent THYMINE and CYTOSINE. The small pyrimidines.

43. Following your teachers directions, let’s build one long strand of DNA

44. A Particular strand of DNA contains 10 adenine molecules. How many thymine will it contain: • 5 • 10 • 20 • Not enough information

45. A strand of DNA is 20% Guanine molecules. What is the percent of thymine in the strand of DNA? • 10 • 20 • 30 • 40 • Not enough information

46. A particular strand of DNA is 40% guanine. What is the percent of adenine in the same strand? • 10 • 20 • 30 • 40

47. The molecule at the location identified by the arrow: • Adenine • Guanine • Sugar • Phosphate • thymine

48. The molecule at the location identified by the arrow: • Adenine • Guanine • Sugar • Phosphate • thymine

49. The molecule at the location identified by the arrow: • Adenine • Guanine • Sugar • Phosphate • thymine

50. The end of the molecule identified by the blue arrows: • Five prime • Three prime