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Title Mystery of DNA replication, The
Subject DNA--Synthesis
Description The 43rd Annual Frederick William Reynolds Lecture.
Creator Lark, Karl G.
Publisher University of Utah Press
Date 1980-03-05
Date Digital 2008-05-29
Type Text
Format application/pdf
Digitization Specifications Original scanned on Epson Expression 10000XL flatbed scanner and saved as 400 ppi uncompressed tiff. Display images generated in PhotoshopCS and uploaded into CONTENTdm Aquisition Station.
Resource Identifier http://content.lib.utah.edu/u?/reynolds,83
Source QP624 .L37
Language eng
Relation Digital reproduction of "The Mystery of DNA replication," J. Willard Marriott Library Special Collections
Rights Digital Image Copyright University of Utah
Metadata Cataloger Seungkeol Choe; Ken Rockwell
ARK ark:/87278/s65q4t2n
Setname uu_fwrl
Date Created 2008-07-29
Date Modified 2008-08-04
ID 319398
Reference URL https://collections.lib.utah.edu/ark:/87278/s65q4t2n

Page Metadata

Title Page20
Description 20 KARL G. LARK began to worry others. Although discontinuous replication survived in vivo and in vitro tests which demonstrated that it was an essential stage in replication, it did not appear to be confined to only one side of the replicating helix. Okazaki, and subsequently others, observed that discontinuous replication could occur on both sides of the double helix. Moreover, some discontinuities in DNA were shown to remain long after replication had taken place in regions far away from the point of replication. In fact, many, if not most, cells appeared to form an altered DNA which later was cut into discontinuous stretches, patched, and put right. It was as if cells had devised a mechanism for insuring that the individual strands of their DNA contained discontinuities. Where continuity of the helix had been the rule, scientists had to accept a molecule with discontinuities constantly patched and possibly repaired. The multiplicity of polymerizing enzymes is related to repair of DNA. Some five to six years prior to the Okazaki-Cairns period, it had been shown that cells possessed the ability to repair damage to their DNA: When DNA is damaged in any way, a complex set of reactions occurs. First, the damaged spot is located. Next, the damage is assessed, and a piece of DNA is cut out. The part that is cut out is then replaced in such a way as to copy the undamaged part faithfully. The enzyme which makes the replacement and does the copying is polymerase I (Romberg's enzyme). It exists in almost one hundred times the quantity of the enzyme which is necessary for replicating the DNA. The reason for this excess is to insure that multiple defects can be repaired at any time if damage occurs to DNA (e.g., during its transcription or replication or as the result of exposure to hazards in the environment). Thus, the integrity of DNA is not due to rigidly maintaining continuity of the structure but in the ability to monitor and repair the molecule to insure a continuity of its information content. Genes are constantly subjected to preventive maintenance. The cell has set up a fail-safe system of supervising the correctness of its own DNA and making sure that its inheritance is almost never distorted. The concept of a patchwork chromosome was receiving emphasis from another observation. Several years earlier, Cairns had made
Format application/pdf
Identifier 026-RNLT-LarKK_Page20.jpg
Source Original Manuscript: The mystery of DNA replication by Karl G. Lark.
Setname uu_fwrl
Date Created 2008-07-29
Date Modified 2008-07-29
ID 319381
Reference URL https://collections.lib.utah.edu/ark:/87278/s65q4t2n/319381