3. The answer is "yes" Polymers A polymer is a big molecule composed of smaller molecules linked together with similar bonds.

4. Synthetic polymers: nylon, kevlar, polyethylene Are these the secret of life?

5. Natural polymers: Cellulose, starch, chitin rubber Are these the secret of life?

6. No. The secret of life lies in a special kind of polymer. SUPER POLYMERS.

7. Super polymers are just like regular polymers, except 1.They are composed of more than one subunit but linked by the same type of bonds 2.The subunits are arranged in a specific order

9. Now, if all the elephants were the same, this would be a regular polymer. In DNA, one kind of SUPER POLYMER, there are four kind of elephants with the names: A, C, G, and T A C GT Note the backbone is the same for each one

15. All SUPER POLYMERS are made by adding one unit at a time on to the tail end of the chain (the 3` end). In the chain above, synthesis is said to proceed 5` to 3`

16. Here's another question: Assume a large field with thousands of A, C, G, and T elephants. At the sound of bell, all the elephants form chains (remember they always grab on to the tail of another elephant). How could you make sure that all the chains stopped with an "A" elephant?

17. SUPER POLYMERS fall into two categories 1.Some act primarily to carry instructions. They are said to be "informational" or "instructional" 2.Some are best at performing operations. They are said to be "operational". They are molecular machines.

18. DNA (deoxy-ribonucleic acid) is the genetic material It is an informational super polymer DNA structure-- a polymer of nucleotides -think of it as the blueprint

19. Nucleotides have : 1) a 5 carbon sugar 2) a ring-shaped nitrogen base 3) a phosphate group

20. Things to notice about the sugar: --sugars can circularize by eliminating an H 2 0 molecule and forming a bond between hydroxyl groups --the carbons in the sugar are given numbers in standard Nomenclature, designated as “prime” to distinguish from carbons on the nitrogen base these numbers are used to distinguish critical sites in The nucleotide and in the DNA strand. ribose is a 5-carbon sugar RNADNA

21. 2’-deoxy-ribose is different from ribose in that it lacks a hydroxyl group (-OH) on the 2’ carbon DNA-2’-deoxy-ribose RNA-ribose The chemical difference associated contributes significantly to the differences between DNA and RNA biochemistry Identify the 5' and 3' groups on your your sugar molecule

22. The OH groups on the 5’ and 3’ carbons are the reactive groups through which nucleotides become joined a nucleotide includes one phosphate group joined at the 5’ position….. PO 4 Add the phosphate group to your sugar ring

23. The polynucleotide chain To form the polynucleotide chain, the oxygen of the 3' hydroxyl group on the chain “attacks” the phosphate of a nucleotide triphosphate eliminating H 2 O and releasing the two outermost phosphate residues. The phospho- diester bond **Notice that the DNA chain is synthesized in a 5’ to 3’ direction.

24. ***There is an asymmetry to the DNA chain! 5’ end--phosphate group 3’ end--free hydroxyl group 5’ end 3’ end Read as: 5’ ATGC 3’

25. Nucleotides have : 1) a 5 carbon sugar 2) a ring-shaped nitrogen base 3) a phosphate group

26. There are 4 bases (units) in DNA: A G C T Adenine and Guanine have 2 rings--purines Cytosine and Thymine have 1 ring--pyrimidines

27. DNA is double-stranded--two polynucleotide chains Hydrogen bonds between bases hold these together G and C have 3 H-bondsA and T make 2 H-bonds 15  GuanineCytosineAdenineThymine

28. DNA strands are arranged in an anti-parallel manner 5’ 3’ 5’ 3’ Complementary (Not “complimentary”)

29. Genes, chromosomes and genomes Gene: DNA devoted to making one specific polypeptide Genes are housed on chromosomes All DNA of an organism makes up its genome Ch. 1-6