SECTION 12.2 AND 12.3DNA

DNA IS DYNAMITE!

Chapter 12Nucleic Acids and Protein Synthesis

I. The Structure of DNA

1. DNA = Deoxyribonucleic Acid2. Contains all information to make genetic

code

I. The Structure of DNA

3. DNA is composed of nucleotides4. Nucleotides are composed of 3 structures:

a) Deoxyribose:b) Phosphate grp:c) Nitrogen base:

DNA Components

I. The Structure of DNA

5. 4 types of Nitrogen bases:a) Adenine: Ab) Guanine: Gc) Cytosine: C d) Thymine: T

I. The Structure of DNA

6. Adenine & Guanine = _______________7. Cytosine & Thymine = _______________

II) The Double Helix

1. DNA is in shape of __________2. Double Helix: 2 nucleotide chains

__________________3. Nucleotides are connected using covalent

bonds a) Nitrogen bases are connected by hydrogen bonds

II) The Double Helix

4. ___ purine will always be connected to _____ pyrimidine

III) Complementary Base Pairing

1. Comp. Base Pairs: Nitrogen bases that pair together to connect the nucleotides of DNA

a) Adenine : ____________b) Guanine :

2. Base Pairing rules:

DNA

Replication of DNA

IV. Replication of DNA

1. Process of copying DNA to create more DNA

IV. Replication of DNA

2. Replication Stepsa) DNA unwinds and unzips –enzyme Helicase breaks

the _______ bondsb) Each chain will act as _________ (pattern) to copy

new nucleotidec) DNA unzips: nucleotide pieces bond to each

exposed half of DNA moleculed) Enzyme Polymerase bonds to monomers to create 2

identical strands

IV. Replication of DNA

*Nucleotide monomers come from digested food*Point where helicase is separating DNA-Replication

Fork

IV. Replication of DNA

3. DNA replication will occur in several different place and the same time

V. Accuracy and Repair

1. Mutation: miss match of complementary base pairs

2. Mutations can be corrected by _____________________________