| Abstract: | The uptake of L-leucine and glycine into pea protoplasts wasstudied under various conditions. The uptake of both L-leucineand glycine was pH dependent with the optimal pH being 4.0 and5.0 for L-leucine and glycine, respectively. A kinetic studyof L-leucine uptake showed that uptake is multiphasic; Km valuesof different phases were 1.1 mol m–3, 33.3 mol m–3and 100 mol m3. A similar analysis for glycine at a concentrationrange of 0.1–10 mol m–3 also showed a multiphasictransport system for it. The uptake of L-leucine at lower concentrations(between0.1–2.0 mol m–3) was energy dependent, since arsenate,azide, dinitrophenol and iodoacetate inhibited the uptake. However,the uptake of L-leucine was not inhibited by ouabain at anyconcentration of L-leucine employed. The uptake of glycine wasnot inhibited by any of these inhibitors suggesting that glycineuptake was not mediated by an active process. Key words: Pea protoplast, L-Leucine, Glycine transport, Active transport, Mediated transport |
