1. Genetic Material DNA Structure & Function

2. (a library of about 1,000 books)
DNA: Amazing Facts
DNA from a single human cell extends in a single thread for almost 2 metres long!!!
It contains information equal to some 600,000 printed pages of 500 words each!!!
(a library of about 1,000 books)

3. General Purpose of DNA:
Stores and transmits genetic information from parent to offspring
DNA stands for
DEOXYRIBONUCLEIC ACID
Size of Chromosome and nitrogen bases:

4. DNA Packaging DNA exists in long fibres called chromatin
DNA in chromatin is wrapped tightly around histones
DNA & histone are further coiled tightly to form nucleosomes
Nucleosomes are eventually wound together to form chromosomes

5. History of DNA Discovery of the DNA double helix
A. Friedrich Miescher – started investigating a compound he found in the nucleus of cells, called it “nuclein” (1869)
B. Rosalind Franklin - X-ray photo of DNA.
(1952)
C. Watson and Crick - described the DNA molecule from Franklin’s X-ray.
(1953)

6. Components of DNA deoxyribose phosphate nitrogen
(1) a 5-carbon/pentose sugar called_____________
(2) a PO4 group or ___________________
(3) a ____________ containing base
phosphate
nitrogen

7. Unit of DNA: The Nucleotide
O=P-O
Phosphate
Group N
Nitrogenous base
(A, G, C, or T)
CH2 O C1 C4 C3 C2 5
Sugar
(deoxyribose)

8. 4 Nitrogenous Bases
Pyrimidines
Purines

9. “A” always pairs with ________
Chargaff’s Rule
“A” always pairs with ________
“C” always pairs with ________
“T” T A
“G” G C

10. DNA Double Helix P O 1 2 3 4 5 P O 1 2 3 4 5 G C T A

11. Overall Structure of DNA
Nitrogenous
Base (A,T,G or C)
“Rungs of ladder”
Double Helix
“Sides of ladder”
Phosphate &
Sugar Backbone

12. Practice Drawing your own DNA molecule
Nucleotide
Base pair

13. Video Clip Answer the questions on the handout.
(4:26 min)
Answer the questions on the handout.

14. Genetic Diversity
Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms.

15. DNA Transcription
DNA can “unzip” itself and RNA nucleotides match up to the DNA strand.
Both DNA & RNA are formed from NUCLEOTIDES and are called NUCLEIC acids.

16. DNA Translation
The cell uses information from “messenger” RNA to produce proteins

17. Why and how is DNA “read”?
It is “read” in order the make proteins out of amino acids.