1. Standard Biology Ch. 28 DNA- Life’s Code
28.1 The DNA Molecule

2. DNA DNA is the chemical that makes up your genes.
Genes make up your chromosomes.
Genes determine your traits.
Chromosomes are located in the nucleus of cells.

3. DNA Structure DNA- deoxyribonucleic acid All living things have DNA
Built like a ladder

4. DNA Structure Base pairing rules: A goes with T and C goes with G
Sides are alternating sugar (deoxyribose) and phosphate
Rungs are nitrogen bases (4 types)
A= adenine
T= thymine
C= cytosine
G= guanine
Base pairing rules: A goes with T and C goes with G

5. Seven Features of DNA
DNA has 2 sides like the up right part of a ladder
Sides are made of sugar and phosphate
There are parts that connect the sides of the ladder (like “rungs”)
The “rungs” are the nitrogen bases
The four nitrogen bases are A, T, C, and G
A goes with T and C goes with G
DNA is a twisted ladder called a double helix

6. DNA and Chromosomes
DNA is in every cell of your body and is the same in every cell
Your DNA is different from every other person’s DNA (except identical twins)
DNA is located in the nucleus and makes up genes and chromosomes

7. Proof that DNA Controls Traits

8. Proof that DNA Controls Traits
Transformation
DNA from the harmful dead bacteria got into the harmless live bacteria and made the harmless bacteria able to cause pneumonia and kill the mice (Fig p. 590)

9. How DNA Works
Works like a computer- reads a signal then transfers to a type of protein
DNA is a base code (3 base code) of nitrogen bases

10. How DNA Works Normal red blood cells: GAGTGAGGCTTC CTCACTCCGAAG
Sickle cell disease red blood cells: GAGTGAGGCTAC
CTCACTCCGATG
Slightly different order of base pairs and codes for a different protein giving a different trait

11. Making Proteins DNA directs the making of proteins in a cell
DNA stays in the nucleus and proteins are made in the cytoplasm at ribosomes

12. DNA to RNA to Protein Two step process: transcription and translation
Transcription (rewrite): RNA is made from DNA; occurs in the nucleus
Translation (change language): protein is made from RNA code; occurs in the cytoplasm at the ribosome

13. Making Proteins RNA is the helper molecule for DNA to make protein
RNA acts like a messenger and carries the code from the DNA to the ribosome

14. Making Proteins Each 3 nitrogen bases is a codon (Like a word)
Each codon has meaning as an amino acid

15. Making Proteins
There are 20 different amino acids, the order of the amino acids gives us all our different

16. How DNA Copies Itself
DNA needs to be copied before cell division can take place (both mitosis and meiosis) Fig p. 594)

17. How DNA Copies Itself DNA untwists DNA unzips
Loose nitrogen bases with a sugar and phosphate fill in on open middle section following base pairing rules (A=T and C=G)
2 new DNA are formed that are exactly alike
REPLICATION

18. How DNA Copies Itself

19. Standard Biology Ch. 28 DNA- Life’s Code
28.2 How the Genetic Message Changes

20. Mutations Change in copying the DNA message
Wrong T, C, A, or G then get the wrong protein made and a different trait
Sickle cell disease- change of T to A
Hemophilia- mutation in sex cell of mother

21. Mutations Causes of mutations Copying mistakes
Radiation- X rays and sun’s UV
Chemicals- tobacco, benzene, asbestos and others

22. Cloning
Have same exact genes and DNA

23. Twins Identical twins: egg 1 + sperm 1 fertilized egg 1 baby baby
Fraternal twins:
egg 1 + sperm egg 2 + sperm 2
fertilized egg 1 fertilized egg 2
baby baby

24. Steps Needed to Clone a Frog
Light frog A- egg cell with nucleus removed
Dark frog B- nucleus from cell of intestine
Add together- get genetic clone of the dark frog
(Fig p. 599)

25. Plant and Animal Breeding
Getting the traits we want

26. Plant and Animal Breeding
Breeding- bringing together 2 living things to produce offspring (plants and animals)
Most crops and livestock today are produced by selective breeding

27. Splicing Genes and Gene Therapy
Splice means to insert
Splicing genes mean to add or insert one gene from one organism into another organism

28. Splicing Genes and Gene Therapy

29. Splicing Genes and Gene Therapy
Gene therapy is the adding of a healthy gene into a person suffering from a genetic disorder
Cystic fibrosis
Hemophilia

30. Splicing Genes and Gene Therapy
Recombinant DNA is formed when DNA from one organism is inserted into another organism

32. Splicing Genes and Gene Therapy
Today use recombinant DNA to produce many vitamins, adhesives, and drugs

33. Splicing Genes and Gene Therapy
Insulin- human gene for insulin added to bacteria so that the bacteria produce human insulin for people with diabetes
Insulin Production for Persons with Diabetes