Permeability to Sugars and Fatty Acids in Polytoma obtusum |
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Authors: | LINDA F CHAPMAN VINCENT P CIRILLO THEODORE L JAHN |
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Institution: | Department of Zoology, University of California, Los Angeles 24, and Department of Biochemistry and Microbiology, Seton Hall College of Medicine and Dentistry, Jersey City 4, New Jersey |
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Abstract: | SYNOPSIS. Whole cells of Polytoma obtusum do not utilize glucose or other hexoses, but cell-free extracts show glucokinase activity having a pH optimum at 8.5 and a Q10 of 2.4 between 0–20°C. Lack of glucom utilization by whole cells reflects a permeability barrier to all sugars. To determine whether inability of acetate-grown cells to utilize butyrate also denoted a permeability barrier, permeability to acetate and butyrate was studied in acetate- and butyrate-grown cells However, acetate-grown cells accumulated C-14 labeled butyrate against a concentration gradient. Therefore inability of acetate-grown cells to utilize butyrate does not denote a permeability barrier. Acetate-kinase activity was consktently demonstrated in cell-free extracts of both acetate- and butyrate-grown cells. Butyrate kinase was consistently found only in butyrate-grown cells. However, the absence of buttymte kinase in acetate-grown cells cannot be claimed since occasionally butyrate kinase activity was demonstrated in extracts of acetate-grown cells. |
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