Studies on the Respiratory Enzymes of Sea Urchin Eggs

Author: Ycas, Martynas Freelandas

Year: 1950

Degree: Dissertation (Ph.D.)

Advisor: Tyler, Albert

Committee Member: Unknown, Unknown

Option: Biology

DOI: 10.7907/ajnr-pa79

Abstract

1. The literature pertaining to the respiratory metabolism of sea urchin eggs is reviewed.

2. Homogenates prepared from the unfertilized eggs of Lythechinus pictus and Strongylocentrotus purpuratus were found to possess enzymatic activity corresponding to the enzymes phosphoglucomutase, oxo isomerase, aldolase, triose phosphate dehydrogenase, lactic dehydrogenase and enolase. Lactic acid accumulates anaerobically in intact eggs. Respiration of homogenates in inhibited by fluoride.

3. Citric, alpha ketoglutaric, succinic and malic acids are metabolized. Respiration is inhibited by malonate and increased by cytochrome o.

4, Spectroscopic evidence is presented for the existence of cytochromes a and b. A method of preparing an insoluble fraction containing these cytochromes is described.

5. It was found that the increased respiration obtainable with dinitrophenol increases faster than the normal respiration during the first eight hours of development.

6. It is concluded that the respiratory pathways of the sea urchin egg are similar to those known to exist in adult organisms.

7. The chemical basis for the similarity or the glycolytic mechanism in most forms of life is discussed.

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