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Mitochondrial Oxidase Systems in Neurospora


Eakin, Richard Timothy (1968) Mitochondrial Oxidase Systems in Neurospora. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/YPY7-V492.


Mitochondrial oxidase systems of Neurospora crassa were investigated with respect to their mechanisms of electron transport and their relationships to respiratory metabolism.

A mitochondrial oxidase system able to utilize dihydroorotic acid as a primary substrate was found and characterized. Another substrate for this system was isolated from yeast extract and identified as 5-N-methylformamido-L-dihydroorotic acid. This system was found to occur in both wildtype and poky, a respiratory mutant. No linkage to the cytochrome chain or to oxidative phosphorylation could be detected.

A succinate oxidase system and NADH oxidase system independent of cytochromes b,a, and a3 were found to occur in both wildtype and in the poky mutant. The system was partially characterized using the poky mutant, which is deficient in cytochromes b,a and a3. It was found that this oxidase system was a part of respiratory metabolism and was linked to oxidative phosphorylation.

Mechanisms of electron transport in these oxidase systems are discussed and models presented.

Possible biological origins and the biological significance of 5 N-methylformamidodihydroorotic acid are also discussed.

The development of poky and wildtype mitochondria during the growth cycle were studied and compared. Differences in morphology were detected using electron microscopy and differences in cytochrome content were detected by absorption spectroscopy. The relationships between the oxidase systems and mitochondrial development are discussed.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Biochemistry and Chemistry)
Degree Grantor:California Institute of Technology
Major Option:Biochemistry
Minor Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Mitchell, Herschel K.
Thesis Committee:
  • Unknown, Unknown
Defense Date:23 May 1968
Funding AgencyGrant Number
U. S. Public Health ServiceUNSPECIFIED
Record Number:CaltechTHESIS:11042016-151827606
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9974
Deposited By: Benjamin Perez
Deposited On:04 Nov 2016 23:13
Last Modified:02 Apr 2024 17:08

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