1. DNA Structure, Protein Production, And Mutations
Chapter 11
DNA Structure, Protein Production, And Mutations

2. I. DNA Structure 1950’s – Protein genetic material
Hershy and Chase proved DNA was genetic material

3. Section 11.1 Summary – pages 281 - 287
I. DNA Structure
DNA (deoxyribonucleic acid) - polymer made of subunits - nucleotides.
Nitrogenous base
Phosphate group
Sugar (deoxyribose)
3 parts: a simple sugar, a phosphate group, and a nitrogenous base.
Section 11.1 Summary – pages

4. Section 11.1 Summary – pages 281 - 287
I. DNA Structure
Four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
Sequence determines function
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Section 11.1 Summary – pages

5. Section 11.1 Summary – pages 281 - 287
I. DNA Structure
Purines – double-ringed nitrogenous bases (adenine and guanine)
Pyrimidines – Single-ringed nitrogenous bases (cytosine and thymine)
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Section 11.1 Summary – pages

6. Complimentary Base Pairs
I. DNA Structure
Complimentary Base Pairs
Always Together
Adenine = Thymine
(2 Hydrogen Bonds)
Cytosine = Guanine
(3 Hydrogen Bonds)

7. I. DNA Structure Double Helix – two strands twisted together
James Watson, Francis Crick, and Rosalind Franklin

8. II. DNA Replication DNA makes an identical copy of itself.
Occurs during S phase of cell cycle
Enzyme (DNA helicase) unzips the DNA
Base pairs are added to strands by DNA polymerase
Passed on via mitosis or meiosis

9. III. Protein Production
DNA contains the information used to produce proteins.
Proteins = chain of amino acids
Overproduction, underproduction, or production at wrong time may have pro’s and con’s
Injury repair 
Cancer 

10. III. RNA DNA RNA Structure Double Helix Single Strand Sugar
Deoxyribose
Ribose
Nitrogen Bases
Adenine thymine Cytosine Guanine
Adenine Uracil Cytosine Guanine
Function
Stores and transmits genetic information
Messenger: takes info from nucleus to ribosome

11. 3-Types of RNA
A. Type 1
Messenger RNA (mRNA) Takes info from nucleus to the ribosome.
Moves to ribosome

12. 3-Types of RNA
B. Type 2
Ribosomal RNA (rRNA) Makes up one of the subunits of the ribosomes
Binds to mRNA to assemble amino acids

13. 3-Types of RNA
C. Type 3
Transfer RNA (tRNA) - delivers amino acids to ribosome .

14. IV. Transcription
Transcription: mRNA made using DNA for a pattern and transfers info to ribosome
Single-stranded unlike DNA replication

15. V. Genetic Code Codon – group of 3 bases code for one A.A.
Ex: UUU or UUA
64 combinations
Some code for instruction (UAA stop; AUG start)
Code “universal”
Enables Translation – tRNA supplies appropriate proteins

16. Section 11.2 Summary – pages 288 - 295
VI. The role of transfer RNA
Amino acid
Each tRNA molecule attaches to only one type of amino acid.
Chain of RNA nucleotides
Transfer RNA molecule
Anticondon
Section 11.2 Summary – pages

17. Section 11.2 Summary – pages 288 - 295
VI. The role of transfer RNA
Ribosome
mRNA codon
Section 11.2 Summary – pages

18. Section 11.2 Summary – pages 288- 295
VI. The role of transfer RNA
The amino acids are joined when a peptide bond is formed between them.
Methionine
Alanine
Peptide bond
Section 11.2 Summary – pages

19. Section 11.2 Summary – pages 288 - 295
VI. The role of transfer RNA
A chain of amino acids is formed until the stop codon is reached on the mRNA strand.
Stop codon
Section 11.2 Summary – pages

20. VII. Genetic Mutations Change in the DNA sequence
Reproductive cells (passed on)
Can have positive or negative results
Body Cells (not passed on)

21. A. Substitution Substitution of a single base pair in DNA.
Changes the amino acid in the protein
THE DOG BIT THE CAT
THE DOG BIT THE CAR

22. B. Deletion/addition Single base added or deleted from the DNA
More harmful than substitution mutation.
THE DOG BIT THE CAT
THE DOB ITT HEC AT

23. 11.3 Section Summary 6.3 – pages 296 - 301
Causes of Mutations
Any agent that can cause a change in DNA is called a mutagen.
Mutagens - radiation, chemicals, and high temperatures.
Can be repaired by enzymes.
11.3 Section Summary 6.3 – pages

24. Biotechnology

25. Comparing DNA Gel Electrophoresis DNA is extracted
DNA is cut using restriction enzymes
Only cut at certain DNA sequences
DNA fragments dumped into one end of porous gel and charge is applied
DNA – (-) charge more towards (+) end
Smaller fragments move faster, larger slower

26. Comparing DNA

27. Comparing DNA
May be used to identify individuals, cataloging endangered species, determining parents, etc
DNA fingerprinting

28. Comparing DNA

29. Genetic Engineering
Transgenic organisms – contain genes from other species
Bacteria
Plants
Animals

30. Bacteria Reproduce rapidly and easily Useful for health and industry
Insulin and other proteins can be produced by bacteria which contain human gene for these proteins
Future?
Cancer fighting agents, raw materials for industry

31. Plants 25%-52% Genetically modified (GM)
Natural insecticide, weed killer resistant, vitamin rich
Future?
Human antibodies
Plastics
Foods resistant to rot

33. Animals Extra copies of growth hormones to grow larger and leaner
Animals with similar immune system as humans for study
Furture?
Bacteria resistant (prevent food poisoning)
Significant amt of proteins (esp in milk)

34. Animals

35. Transformation
Cell takes in DNA from outside the cell, DNA becomes part of the cell’s DNA
In bacteria
Plasmid – small, circular DNA molecule which joins to foreign DNA
Sequence is replicated
Plasmids contain genetic markers - gene which allows us to tell if bacteria took the DNA
Select transformed bacteria for reproduction

36. Transformation
Pg 328

37. Human Genome Human Genome Project DNA Fingerprinting Map out each Gene
Mapping out all pairs (3 billiion)
DNA Fingerprinting
Map out each Gene
Diagnose genetic disorders
Gene therapy

38. Human Genome
Gene Therapy – insertion of normal genes into cell

39. Ethics? Genetically modified organisms? Stem cell research?
Build-a-Baby?