1. DNA and RNA

2. Add to Table of Contents
p. 10 DNA/RNA Vocabulary
p. 11 DNA/RNA Structures
p. 12 Complementary Base-Pairing

3. DNA Deoxyribonucleic Acid Double-stranded Double-helix structure
Made of nucleotides - each nucleotide has 3 parts (remember PBS)
Phosphate group
Bases – Adenine (A), Guanine (G), Cytosine (C), Thymine (T)
Sugar – 5-carbon sugar called deoxyribose
Only one type of DNA

4. RNA Ribonucleic Acid Single-stranded Made of nucleotides also
Phosphate group
Bases – Adenine (A), Guanine (G), Cytosine (C), Uracil (U)
Sugar – 5-carbon sugar called ribose
Three types of RNA
mRNA – messenger RNA
tRNA – transfer RNA
rRNA – ribosomal RNA

5. On the back of your notes:
Turn the page sideways, and complete a Venn Diagram summarizing the similarities and differences between DNA and RNA.
DNA
DNA
RNA

6. Complementary Base-pairing
Adenine pairs with Thymine; Cytosine pairs with Guanine
In RNA, Adenine pairs with Uracil

7. Base pairing rules
Erwin Chargaff (Chargaff’s Rule) determined that the amount of Adenine is equal to the amount of Thymine and the amount of Cytosine is equal to the amount of Guanine.
So…
%A = %T
%C = %G
A+T+C+G = 100%

8. A = 23 If A = 23, then T = 23 T C + G 100 A = 23 T = 23
Do some math… If Adenine makes up 23% of the DNA, how much Cytosine is there?
A = 23 If A = 23, then T = 23 T C + G 100 A = 23 T = 23 46
100 – 46 = 54
54 ÷ 2 = 27
Answer: 27% Cytosine

9. Replication Copying DNA Where? In the nucleus
When? S phase of Interphase
1 Strand  2 Complementary Strands
Remember:
A pairs with T
G pairs with C

10. Replication - Remember: A pairs with T G pairs with C
TTA CGG TAG AAT CCC CGG
AAT GCC ATC TTA GGG GCC

11. Replication – Check Your Answers
1. TTA CGG TAG AAT CCC CGG
AAT GCC ATC TTA GGG GCC
2. ATA GTA TTG ACC CGT AAG
TAT CAT AAC TGG GCA TTC
3. CCG GAA AAT CGA AGT ATA
GGC CTT TTA GCT TCA TAT
4. TAG CAT AAC TAC GAT GGA
ATC GTA TTG ATG CTA CCT
5. GGA GTA CCA TAT GAT CCT
CCT CAT GGT ATA CTA GGA

12. History of DNA James Watson and Francis Crick
Discovered the 3- dimensional structure of the DNA molecule.
Called it the Double Helix
Rosalind Franklin: Provided x-ray evidence of the DNA helix structure.

13. Double Helix 2 strands twisted together like a ladder.
Complementary strands– fit together but are opposites.

14. Differences DNA RNA Double strand Sugar: Deoxyribose
Location: ONLY in the nucleus.
Job: A list of instructions
Nitrogen-containing bases:
Adenine
Guanine
Cytosine
Thymine
RNA
Single strand
Sugar: Ribose
Location: Throughout the cell
Job: Carries out instructions of DNA
Nitrogen-containing bases:
Adenine
Guanine
Cytosine
Uracil

15. DIFFERENCES (CONT) There is only ONE type of DNA
There are 3 types of RNA…
Messenger RNA (mRNA): RNA strand created from the original DNA strand.
Ribosomal RNA (rRNA): Makes up ribosomes.
Transfer RNA (tRNA): carries amino acids from the cytoplasm to the ribosome during protein synthesis.

16. What holds DNA together?
There are weak hydrogen bonds that hold the base pairs together.
They are broken to allow the molecule to replicate or be transcribed.