BIO 311C Chapter Notes - Chapter 16: Euchromatin, Endergonic Reaction, Covalent Bond
Document Summary
What are the essential properties of a molecule of heredity: sufficient variability to store information, able to make copies of the information, information must be accessible for gene expression. Bacteria strains that cause pneumonia: when nonpathogenic bacteria mixed with dead pathogenic bacteria, they and descendants became pathogenic again. Something from pathogenic bacteria left and went into the nonpathogenic bacteria. Hershey chase experiment: used radioactive isotope of sulfur to tag protein and radioactive phosphorus to tag dna. Concluded that the dna injected by the phage must carry the genetic information that makes the cell produce new viral dna and proteins. Chargaff found out that different organisms have different base compositions of dna. Chargaff also found dna base ratio: a-t, c-g. Base composition of dna varies between species. For each species, the percentage of a and t, c and g bases are roughly equal. Adenine and guanine are purines base with two organic rings.
