1. DNA

2. What is DNA? Contains all genetic information of the entire organism
Located in the nucleus of all cells (with a few exceptions!)
mature red blood cells have no nucleus
sex cells have half the amount of genetic information (haploid)
A “full set” in humans is 46 chromosomes
Made up of 23 pairs (diploid)

3. But not in all animals! Organism # of Chromosome Pairs Human 23
Drosophila (fruit fly) 4
E.coli (bacteria)
Mosquito 3
Fly
Frog 18
Cat 19
Chimpanzee 24
Horse 32
Dog 39
Onion 8
Peanut 12

4. DNA spends most of its time in a long string called chromatin
During cell division, chromatin coils up tightly to form chromosomes

7. the section of DNA that codes for a protein is called a gene

8. DNA -> RNA -> Protein (made of amino acid)

9. DNA Structure DNA is made of nucleotides composed of 3 parts DNA:
5 carbon sugar: deoxyribose
one nitrogenous base (4 possible options!)
phosphate group
DNA:
Deoxyribo-
Nucleic acid

10. There are two types of nitrogenous bases:
1. Purines
-Adenine (A) and Guanine (G)
-2 fused rings
2. Pyrimidines
-Cytosine (C) and Thymine (T)
-only one ring
Adenine ALWAYS bonds with thymine
Guanine ALWAYS bonds with cytosine
-this is called complimentary base pairing

12. Computer information is stored as zeros and ones (binary)
When we write information we use 26 letters (plus some extra numbers and symbols)
Words can be short
Computer information is stored as zeros and ones (binary)
This takes a lot of zeros and ones to give useful information (very long “words”)
E.g. the letter a is
How big is the human genome?
Only uses 4 letters (A, C, G, and T)

13. How long do you think the human genome is? (in bases)
The human genome has approx. 3 billion base pairs
That’s 3,000,000,000 bases!
Printing this out would take roughly 150,000 telephone book pages

15. DNA looks like a twisted ladder
This arrangement is called a double helix

16. Alternating sugar and phosphates make up the backbone (the “rails” of the ladder)
Bases make up the “rungs” and are held together by weak hydrogen bonds