Starter

• I will pass the nucleotides out.

• Cut the nucleotides out (other than the base you don’t have to cut out the lines.

• Create a DNA strand using this sequence:5-ATGCAAGTCCGT-3

DNA Structure

Where is DNA located?

• In the nucleus

Nucleus

Structure

• Double Helix

• Nucleotide Strands– Basic Building Block of DNA– Composed of

• Sugar (Deoxyribose)• Phosphate group• Base (A, T, G or C)

What are the bases?

– A – Adenine

– G – Guanine

– T – Thymine

– C - Cytosine

Line Up

• 5’ to 3’– Complement strand is

opposite

Which bases join together?

• A with T

• C with G

• How are they joined?– Hydrogen Bonds

• These strands are complements! Allowing for DNA replication to take place.

Starter

• Describe the structure of DNA.

Chromosome numbers• Humans: 46• Aquatic Rat: 92 (tied for most in mammals)• Cat: 38• Chimp: 48• Cotton: 52• Cow: 60• Kangaroo: 12• Adders Tongue: 1200 or 1260• Strawberry: 56

DNA Replication

DNA Replication

• The original strands act as parent strands for the replication

• Each receives a new, complementary strand

• Enzymes do all the work

• Produce 2 identical DNA strands

How does Replication happen?

• DNA unwinds– Hydrogen Bonds are

broken

Building of new strands…

• New strand begins to build

• Cannot build it from scratch– Builds on pre-existing strand (parent strand)

• Remember…it will build a Complementary strand– A to T, T to A– G to C, C to G

Two Identical Strands

• When the replication is complete, you are left with two, identical strands of DNA!

Assignment• Read pages 229 – 234

– Ignore pyrimidines and purines– Ignore DNA polymerase– Place a sticky note by something that you

understand and can relate to what we have talked about so far.

– Place a sticky note by something that you don’t understand.

• Answer the concept checks– 11.2 (1-3)– 11.3 (1-3)