Structure of DNA Take two minutes to fill in as many parts of the DNA model as you can from your memory. 2 minutes This ‘sand timer’ will start on a mouse click anywhere on the slide. The ‘sand’ will drain from the top section to the lower section and when completed will show the word ‘End’. To change the timings of this timer, you need to enter the animation settings, and change the timings for the Isosceles Triangles. There will be 2 that need changing (to the same amount) – one animates the top triangle emptying, whilst the other animates the bottom triangle filling. When you change the timings these have to entered as a number of seconds. End

Before we fill in the DNA model… let’s remember the song! We love DNA made of nucleotides. Phosphate, sugar, and a base bonded down one side. Thymine and adenine make a lovely pair, cytosine without guanine would feel very bare.

T A P S S P G C P S S P A T P S S P A T P S S P C P G S S P G C P S S Sugar-Phosphate backbone Sugar-Phosphate backbone Nitrogen Bases T A P S S P G C P S S P A T P S S P A T P S S P C P G S S P G C P Nucleotide S S P

T A P S S P G C P S S P A T P S S P A T P S S P C P G S S P G C P S S Sugar-Phosphate backbone Sugar-Phosphate backbone Nitrogen Bases T A P S S Hydrogen Bonds = weak bonds P G C P S S P A T P S Covalent Bonds = Strong bonds S P A T P S S P C P G S S P G C P Nucleotide S S P

What is this graphic showing us?

Yeast A=T so 35+35= 70 for AT combined. 100-70=30 left for CG combined. 30/2= 15% C and 15% G A will only pair with T, C will only pair with G. v It shows that all organisms only have 4 nitrogen bases: ATCG

DNA vs RNA Video https://www.youtube.com/watch?v=0Elo-zX1k8M

Nearpod! Go to www.nearpod.com on your device. There is also an app called Nearpod that you can download if you’d like. Make sure that you are holding your phone/ipad sideways during the presentation.

Complete the Review as a Team. To carry the genetic code to make proteins. TCTACGTAG GATCCATGC Nitrogen bases Weak Hydrogen bonds Strong covalent bonds nucleotide Nitrogen base phosphate sugar

Deoxyribose DNA Replication Identical 12% 38%

Wrap Up! Complete the exit ticket.