Life Sciences Commons^™

Studies On The Roles Of Atp In Nitrogenase Catalysis, Wei Wu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogenase is the enzyme that catalyzes the reduction of nitrogen to ammonia in a reaction requiring MgATP hydrolysis. Two component proteins of nitrogenase are the iron protein (Fe protein) and the molybdenum-iron protein (MoFe protein).

Nitrogenase contains two nucleotide binding sites. During catalysis, the Fe protein binds two MgATP first. The conformational changes induced upon MgATP binding allow the Fe protein to associate with the MoFe protein. After the formation of the Fe protein-MoFe protein complex, a single electron is transferred from the Fe protein to the MoFe protein, an event that is coupled to MgATP hydrolysis in the Fe …

Comparison Of Microbial Activity In Desert Soils Of The Western United States, Patricia Ann Trujillo Y Fulgham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soils from four regional deserts, Great Basin, Sonoran, Chihuahuan, and Mojave, were collected at times throughout the year which would best exhibit microbial response to moisture or vegetation. The soils were analyzed for several chemical and physical properties. Biological and biochemical characteristics, namely respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, nitrification potential, and microbial numbers, were measured.

The soils exhibited fluctuations in microbial activity as measured by respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, and nitrification potential during different moisture seasons.

Increase in soil moisture as modified by precipitation did not cause a significant difference in respiration or …