1. Discovering DNA

2. Let’s take a closer look at DNA…
D = deoxyribo
N = nucleic
A = acid
DNA structure is the double helix
It looks like a twisted ladder!

3. Nucleotides Are made up of… - sugar - phosphate - nitrogenous base
The “sides” of the ladder are sugar and phosphate molecules
The “rungs” of the ladder are made up of complementary nitrogenous bases

4. There are FOUR different bases:
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
The bases ALWAYS pair together like this:
Adenine ---- Thymine
Cytosine ---- Guanine

5. A few more definitions…
Gene: Section of DNA that “codes” for a specific protein (instructions for making it)
Genome: All an organism’s genes
The human genome contains over 20,000 different genes!

6. Activity #1 Cut out the shapes I have provided for your group
“D” – deoxyribose (sugar)
“P” = phosphate
A, G, T, C are the nitrogenous bases
Glue your shapes together to create FOUR nucleotides
Glue the nucleotides to your group’s sheet by lining up the complementary bases
Circle one nucleotide
Label… sugar
phosphate
name each of the four nitrogenous bases

7. Activity #2
We’ll watch the video together on DNA, Chromosomes, Genes and Traits
If you need to review the video at home, I will post a link to it on our class Blog!
Complete the Video Recap sheet for next class