DNA

What does DNA stand for?

Deoxyribonucleic Acid DNA stores genetic information

in the nucleus. DNA is the genetic blueprint, or recipe, for making all living things.

Almost every cell in your body contains DNA, and you have five trillion (5,000,000,000,000) cells in your body. THAT’S A LOT OF DNA!

What does DNA look like?

The shape of DNA is called the Double Helix. It looks like a twisted ladder or a spiral staircase.

The double helix twists DNA so that it fits into the nucleus.

ARE YOU PAYING ATTENTION?

Where is DNA found?

NucleusHow is DNA shaped?

Double Helix, Spiral Staircase, Twisted Ladder

DNA is made up of Nucleotides. To form a DNA

molecule, thousands of nucleotides are joined in a long chain.

Each Nucleotide has 3 parts:

1. Phosphate group

2. Deoxyribose- sugar

3. Nitrogenous Base Adenine-AThymine-T

Guanine-G

Cytosine-C

What are the 3 parts of a nucleotide?

What are the 3 parts of a nucleotide?

1. Phosphate group

2. Deoxyribose- sugar

3. Nitrogenous Base

What are the 4 Nitrogenous Bases?

1. Adenine 3. Guanine

2. Thymine 4. Cytosine

Base Pairing

Adenine base pairs with Thymine (A-T)

Guanine base pairs with Cytosine (G-C)

The sequence of these bases determines all of the traits of living things.

Bases are paired and held together by hydrogen bonds (H-bonds).

What is the complimentary DNA strand?

A T G C T T A G C C _________________

Purines – have 2 rings Adenine and Guanine

are purines

Pyrimidines –have one ring

Cytosine and Thymine are pyrimidines

Guanine and Cytosine=3 Hydrogen Bonds

Adenine and Thymine= 2 Hydrogen Bonds

Eukaryotic Cell Structure

In eukaryotes (animal and plant cells) DNA is found in the nucleus.

The function of the nucleus is to control the cell’s activities.

Where is DNA found?

Prokaryotic Cell Structure

Prokaryotes do not have a nucleus so the DNA floats around in the cytoplasm.

Examples of prokaryotes are bacteria.

Chargaff’s Rule

Whenever you see Adenine (A), you will see ________________in DNA.

Whenever you see Guanine (G), you will see ________________ in DNA.

This is also called BASE PAIRING.

Chargaff’s Rule

Whenever you see Adenine (A), you will see THYMINE (T) in DNA.

Whenever you see Guanine (G), you will see CYTOSINE (C) in DNA.

This is also called BASE PAIRING.

Replication Animation

http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html#