Date of Award

5-1997

Degree Type

Thesis

Degree Name

Departmental Honors

Department

Biology

First Advisor

Gregg J. Prelgozli

Abstract

All organisms must respond to different environmental stresses. For unicellular organisms, the most important source of stress is starvation or nutrient depletion. These microscopic life forms must respond to a constantly changing food supply in which short periods of nutrient availability are interspersed with extended periods of famine. In addition to complete starvation, these organisms are affected by other chemical changes, such as forced switching from a desirable to a less desirable carbon source, and physical changes, such as heat shock. Many microorganisms respond to such stresses by entering a different phase of their life cycle. For example, the budding yeast Saccharomyces cerevisiae responds by forming ascospores (1). Another unicellular organism, the slime mold Dictyostelium discoideum responds to stress by fruiting body formation (2). Although multicellular organisms are relatively less susceptible to drastic changes in nutrient availability, they still must respond to stresses including nutrient deprivation, heat shock, and toxins. Many multicellular organisms, including mammals, respond to stress by altering their lipid metabolism (3, 4).

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Biology Commons

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