1. Warm-up: DNA What does DNA stand for? Where do we find DNA?
How do crime scene investigators use DNA to solve crimes?

2. NUCLEIC ACIDS Flow of biological information: DNA RNA protein trait
DNA deoxyribonucleic acid carries the genetic code (stores and transmits the genetic information
from one generation to the next)
parents offspring
DNA is a type of organic compound and an example of a Nucleic Acid
Definition organic compound: compound containing Carbon & made from a living organism
B. Chromosomes are made of DNA and are located in the nucleus only

4. Model of DNA:
The model was developed by James Watson and Francis Crick.
They received a Nobel Prize in 1962 for their work.
First picture of DNA (X-ray) – Rosalind Franklin
The model looks like a twisted ladder – double helix

5. Watson
Crick
Died in 2004

6. RECALL… Nucleotides are the building blocks (monomer) of DNA (polymer)
One Phosphate + one Sugar + one Base = one nucleotide
Nucleotides are the building blocks (monomer) of DNA (polymer)

7. Untwisted it looks like this:
The sides of the ladder are
P = phosphate group
S = deoxyribose sugar
The steps of the ladder are C, G, T, A = nitrogenous bases (contain Nitrogen)
Purine Pyrimidine
A and G = purines
T and C = pyrimidines
Nucleotide

8. 2 H bonds
pairs
A = adenine
T = thymine
3 H bonds
pairs
C = cytosine
G = guanine

10. When would your body need more cells?
How do we get more or new cells?

11. II. DNA Replication
A. Cell division produces 2 daughter cells that are genetically identical to each other and genetically identical to the parent cell
B. Remember that for this to happen, DNA in the parent cell must be replicated (copied) before cell division

12. STEP 1
STEP 2
Hydrogen bonds between base pairs are broken by the enzyme Helicase and DNA molecule unzips
DNA molecule separates into complementary halves

13. STEP 3
Nucleotides match up with complementary bases
Free nucleotides
abundant in nucleus

14. STEP 4 New Strand Original Strand
Nucleotides are linked into 2 new strands of DNA by the enzyme, DNA polymerase—DNA Polymerase also proofreads for copying errors
New Strand
Original Strand

16. III. Ribonucleic acid – RNA -- acts as a
III. Ribonucleic acid – RNA -- acts as a messenger between DNA and ribosomes, and carries out the process by which proteins are made from amino acids.
Protein = polymer Amino Acids = monomer
A. Different from DNA:
1. RNA’s sugar -- ribose
DNA’s sugar – deoxyribose
2. RNA – single strand of nucleotides
DNA – double strand of nucleotides (double helix)

17. 3. RNA has uracil instead of – thymine
When RNA pairs with DNA to get its code:
RNA cytosine (C) pairs with DNA – guanine (G)
RNA guanine (G) pairs with DNA – cytosine (C)
RNA adenine (A) pairs with DNA – thymine (T)
RNA uracil (U) pairs with DNA – adenine (A)
 4. RNA found – inside and outside nucleus
(small – single strand)
DNA found – inside nucleus only
(large – double strand)

18. B. 3 types of RNA involved in Protein Synthesis– mRNA messenger RNA
tRNA transfer RNA
rRNA ribosomal RNA

20. found in and out of nucleus
Complete the chart by reading each term or phrase and placing a check in the appropriate column.
DNA
RNA
Both
Deoxyribose 
Ribose
double stranded
single stranded
nucleotides
found in nucleus only
found in and out of nucleus
Cytosine
Guanine
Adenine
Thymine
Uracil
double helix
replication