1. Molecular Genetics Protein Synthesis One Gene-One Polypeptide

2. Archibald Garrod (1857-1963) Image from: http://www.dnaftb.org/13/bio.html British physician who studied metabolic defects in newborns noticed family history of certain illnesses

3. Alkaptonuria Image from: http://www.gfmer.ch/genetic_diseases_v2/gendis_detail_list.php?cat3=18 hereditary disease that caused urine to turn black due to accumulation of alkapton (homogentisic acid)

4. Garrod’s hypothesis? newborns who were fed extra phenylalanine (an amino acid) had increased blackness in urine SO…alkaptonuria must be caused by defective enzyme AND…the defective enzyme must be caused by an error in hereditary material

5. Garrod’s hypothesis Image from: http://www.nature.com/scitable/topicpage/cell-metabolism-14026182 defective alkapton-metabolizing enzyme part of a metabolic pathway “inborn error of metabolism” (1923)

6. Phenylalanine Metabolism Image from: http://wiki.cstl.semo.edu/agathman/Proteins%20and%20genes.ashx

7. Beadle & Tatum (Image from: http://sandwalk.blogspot.com/2008/05/nobel-laureates-george-beadle-and.html) American geneticists published paper (1941) with findings on relationship between genes & enzymes in red bread mould, Neurospora crassa

8. Neurospora crassa Image from: http://publications.nigms.nih.gov/thenewgenetics/livinglab.html

9. Beadle & Tatum “normal” N. crassa was able to grow on minimal nutrient medium (i.e. it was able to synthesize all needed amino acids and vitamins) “mutant” strains of N. crassa were created through exposure to X-rays or UV radiation

10. Beadle & Tatum Image on next slide from: http://www.mun.ca/biology/scarr/Arginine_nutritional_mutants.html mutant strains were unable to grow on minimal nutrient medium for some mutant strains, addition of arginine to the minimal nutrient medium resulted in growth reaction pathway for synthesis of arginine was determined through experimentation

12. Arginine Synthesis Image from: http://www.flickr.com/photos/agathman/5469134899/

13. One Gene-One Enzyme Beadle & Tatum’s work resulted in the one gene-one enzyme hypothesis this hypothesis is more accurately known as the one gene-one polypeptide hypothesis

14. Vernon Ingram (Image from: http://www.pnas.org/site/misc/ingram.shtml) German-American Biology professor (1924-2006) who studied sickle-cell anemia

15. Sickle-cell anemia (Image from: http://www.blackpast.org/?q=aah/sickle-cell-anemia) hereditary disorder red blood cells contain abnormal hemoglobin, causing crescent shape cause difficulty with blood flow

16. Sickle-cell anemia Image from: http://gassama.myweb.uga.edu/ sequenced the hemoglobin protein determined the difference between hemoglobin of normal RBCs and sickle cell anemia RBCs

17. Hemoglobin ß-chain Image from: http://library.thinkquest.org/17109/diseases.htm

18. Test yourself… http://highered.mcgraw- hill.com/sites/0072437316/student_view 0/chapter14/chapter_quiz.htmlhttp://highered.mcgraw- hill.com/sites/0072437316/student_view 0/chapter14/chapter_quiz.html

19. Animations Beadle & Tatum experiments (excellent slideshow): http://www.dnaftb.org/16/animation.html Beadle & Tatum (narrated animation…a bit dry) http://wps.prenhall.com/wps/media/objects/1552 /1589869/web_tut/21_04/21_04_01a.swf