Structure Notes

Mapping of Concept DNA Replication DNA Location Structure

Where is it located? Prokaryotic Cells: The cytoplasm Eukaryotic Cells: The nucleus (in the center of the cell)

What is DNA? 1. Deoxyribonucleic Acid 2. A Double Helix Chain

What is a gene? Our DNA is made of many genes linked together (like recipes in a cookbook) A gene is the directions for making 1 protein. Hello, I’m Gene!!!

Functions of DNA: Why is it important? 1.Carries genetic information from parent to child 2.Used for making proteins in our bodies

STRUCTURE of DNA 1. A Nucleotide = Basic Unit of DNA

3 Parts of a Nucleotide 1. Sugar (deoxyribose) 2. Phosphate (PO 4 ) 3. Nitrogenous Base

Here is a nucleotide…  the phosphate (PO 4 )  the sugar (deoxyribose)  a nitrogenous base

PARTS 1 and 2 The sugars and the phosphate groups are the same in a given DNA strand, but the nitrogenous bases differ.

Nitrogenous Bases A – Adenine T – Thymine C – Cytosine G – Guanine

Which nitrogenous bases bond together? A=T C=G Chargaff’s Rule for base pairing: A bonds with T C bonds with G

DNA Replication: Q: Why does DNA replicate (copy itself)? A: When cells divide, each new cell needs an exact copy of the DNA that was in the old cell.

STEP 1: Double Helix Untwists

STEP 2: An enzyme unwinds and separates the two DNA strands

As the weak Hydrogen Bonds break…... …the double helix chain opens Enzyme

Step 3 : New nucleotides enter and bond to open bases new nucleotide

STEP 4: Two identical chains are formed and they re-twist into the double helix shape.

The Future???? DNA ANIMATION HHMI CLIP DNA SONG