DNA Replication Protein Synthesis DNA Deoxyribonucleic Acid 1

DNA Replication & Protein Synthesis

DNA (Deoxyribonucleic Acid) 1. What type of organic molecule is DNA? – Nucleic Acid 2. Where does DNA replication occur? – Nucleus 3. During which phase of the cell cycle does DNA replication occur? – S-phase of Interphase

DNA Building Blocks 4. Building blocks of nucleic acids are nucleotides. – The three parts of a nucleotide are: deoxyribose sugar, phosphate, and nitrogenous base.

DNA Structure 5. The structure of DNA is a double helix, which looks like a coiled ladder. – The sides of the ladder alternate between a deoxyribose sugar and a phosphate, bound together by covalent bonds. This is sometimes called the “backbone” of the DNA. – The steps of the ladder are nitrogenous bases with hydrogen bonds between them.

Discovery of DNA’s Structure – Who is credited with the discovery of the structure of DNA? Watson & Crick

Nitrogenous Bases 6. There are four types of nitrogen bases in DNA: – Cytosine bonds to Guanine – Adenine bonds to Thymine Label Diagram

DNA Replication 1. Helicase unzips the double helix, breaking the hydrogen bonds between nitrogen bases. 2. DNA Polymerase comes in and begins to add new nucleotides to the parent strand. 3. When process is complete, two identical strands of DNA are produced.

DNA Replication

DNA Replication Draw helicase & DNA polymerase

Base Matching • Unzip with helicase. • Add matching bases.