DNA www.nerdscience.com

What is DNA? Polymer made of nucleotides Nucleotides are made of: a simple sugar (deoxyribose sugar) a phosphate group a nitrogen base It contains the code to make proteins! Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall. 12-1

DNA (deoxyribonucleic acid) Found in nucleus Coils to form chromosomes Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

Covalent bonds hold sugar and phosphate groups together Hydrogen bonds hold nitrogen bases together Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

The Four Nitrogen Bases are Adenine (A) Thymine (T) Guanine (G) Cytosine (C) Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall. 12-1

Purines & Pyrimidines Purines: Include bases Adenine & Guanine. Have a double ring structure. Pyrimidines: include bases Thymine, Cytosine, and Uracil. Have a single ring structure.

Nitrogen Base Pairs Adenine pairs with thymine. A bonds to T T bonds to A Guanine pairs with cytosine. C bonds to G G bonds to C Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

Hydrogen bonds weak bonds hold nitrogen bases together bonds A -T and G - C Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

Watson and Crick 1950’s Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall. 12-1

Watson and Crick Discovered the structure of DNA DNA is double stranded Forms double helix spiral ladder

Watson and Crick A bonds to T C bonds to G They discovered that : Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall. 12-1

Order of the nitrogen base pairs is the genetic code. Order of the nitrogen base pairs (A,T,G,C) determines the traits of the individual. Order of the nitrogen base pairs is the genetic code. Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

Replication of DNA Process of copying DNA Takes place in nucleus Happens before cells divide by mitosis or meiosis Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

DNA Replication

DNA Replication Allows daughter cells formed from mitosis to be identical to parent cell. Allows four sex cells with ½ the genetic material ( ½ the number of chromosomes) to be formed in meiosis Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

How DNA Replicates Hydrogen bonds break (Helicase) DNA molecule unzips between nitrogen base pairs (A-T or T-A and C-G or G-C) Nucleotides (Nitrogen base, sugar, and phosphate groups) move from cytoplasm into nucleus Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

Replication of DNA Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.

How DNA Replicates (cont’d) Nucleotides moving into nucleus bond with original strands of separated DNA (DNA Polymerase) Two strands of DNA are formed Each double stranded DNA molecule has one strand of old and one strand of new DNA (semi-conservative process). Miller, K. R., & Levine, J. S. (2005). Chapter 12: DNA and RNA. Prentice Hall biology (North Carolina ed., pp. 286- 317). Upper Saddle River, N.J.: Prentice Hall.