Genetics Feb 21 Chapter 7 - Chapter7 Lecturenotes...

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Chapter 7   Lecture notes Hereditary material Biologists hypothesized that hereditary material should have the following three properties:  on  next quiz 1.  Have information content.  You see here hereditary material has the genetic material to keep  the certain pigments 2.  Allow relatively faithful replication to provide for the kind of stability necessary. 3.  Allow for rare changes in the information content that are capable of permanence.   The development of the hypothesis that DNA is the genetic material. By the 1930’s biologists began to speculate as to what sort of molecules could have these  properties. ** Protein and not DNA was thought to be the genetic material just prior to the DNA hypothesis for  two reasons.  -space filling molecule 3Cro 1.  Biologists believed that the genetic material would have to be complex  1 to carry all the  information 2  to code for all the various life forms. 3   Biologists knew that protein was more complex than DNA because they were aware that protein  is composed of 20 different monomers (amino acids) and that DNA was composed of only 4 monomers (The A, T, C, and G nucleotides). 2.  Biologists also reasoned that the genetic material would need to be present in all parts of the  cell  (ubiquitous) means its all over the place  in order to control all the activities of the cell. Biologists knew that protein was found in all portions of the cell and that the DNA was found  primarily in the nucleus. Until  the mid-1940’s there appeared to be no method to directly approach the question of the  gene’s chemical structure. Therefore, biologists began to approach the nature of the gene by attempting to determine how  genes function within cells.
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The first clues as to how genes function came from studies of humans. ** Early in the twentieth century  Archibald E. Garrod , an English physician, (p 187) hypothesized  that several human  diseases show metabolic defects in the metabolism. **** 1. Gerrod is the first to hypothesize that human disease could have genetic disorder         2. He focused our attention and said the function of the gene is to control metabolism -biproduct there is certain human diseases that cause ***quiz?? He coined the idea that these defects were  “inborn errors in metabolism.” ****2 nd  big contribution restated  Garrod’s observations focused attention on  metabolic control  as a  primary way in which genes function. _____________________________________________________________________________ _ Another group focusing on genes controlling metabolism
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This note was uploaded on 11/11/2009 for the course BIO Genetics taught by Professor Saxena during the Spring '08 term at University of Texas at Austin.

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Genetics Feb 21 Chapter 7 - Chapter7 Lecturenotes...

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