Descripción: FORMATO MENSUAL DE INFORMACIÓN REQUERIDA
S-89-S-4up
Descripción: S-89-S-4up
Descripción: instrucciones para vida y ministerio
A
B
C
Figure A-C: Test tubes having a brim-filled of 0 .001% Methylene blue; Fig. A with and without Mung Bean seedlings before incubation; Fig. B- after incubation within 24 hours and Fig. C-after aeration Test tube with 0.001% Methylene blue
Color Original
After 24 hours
After Aeration
With Germinated Mung bean seedlings
Blue
Colorless
Light Blue
Without germinated Mung bean seedling
Blue
Blue
Blue
The test for dehydrogenases has a set -up of 2 test tubes brim-filled with 0.001% methylene blue. The first test tube contains 10 grams of germinated Vigna radiata seedling while the second one doe sn’t contain Vigna radiata and serves as the control. Both test tubes were covered by a stopper stopper and incubated overnight. After 24 hours there was a change of color in test tube 1. From blue it becomes colorless and the test. tube 2 remains unchanged (see figure B). After ae ration, the solution in test tube 1 becomes blue in color again (see figure C).
During respiration, hydrogen atoms are removed from g lucose molecules by enzymes called dehydrogenases and passed to various chemicals called hydrogen acceptors. As the hydrogen atoms pass from one hydrogen acceptor to another, energy is made available for chemical reactions in the cell. In this way, substances such as glucose provide energy for vital reactions in living organisms. In this experiment, a dye called methylene met hylene blue acts as an artificial hydrogen acceptor. When t his dye is reduced by accepting hydrogen atoms it goes colourless.
O2 + (dissolved)
methylene blue ---> (colorless) (reduced form)
methylene blue (color blue) (oxidized form)
Although a great deal of information has been amassed c oncerning dehydrogenases in animal tissues, there was for a long time little evidence that certain of these important enzymes even existed in plants. Malic and citric dehydrogenases were reported in 1929 in cucumber seeds (Thunberg 1929), but it was not until 1939 that succinic dehydrogenase was found, first in pollen. (Okunuki 1939) and then in certain other tissues (Damoran1941). Nevertheless, the apparent absence or near-absence of succinic dehydrogenase in some tissues (Bartlett 1943) as well as the occasional reports of the presence o f individual enzymes (Thunberg 1938) seemed to indicate that the dehydrogenases, at least those of the 4carbon and 6 carbon acids, were distributed only sporadically. It was during this period that the tricarboxylic acid cycle of Krebs (Krebs 1943), embodying many of these dehydrogenases, was becoming accepted as the main pathway of respiration in animal tissues. Respiration studies in plants (Bonner 1948) pointed in the same direction.
Reference: CARL A. PRICE AND KENNETH V. THIMANN BIOLOGICAL LABORATORIES, HARVARD UNIVERSITY, CAMBRIDGE, MASS, March , 1954 THE ESTIMATION OF DEHYDROGENASES IN PLANT TISSUE1
DAMODARAN, M. and VENKATESAN, T. R. Amide synthesis in plants. I. The succinic oxidase system in plants. Proc. Ind. Acad. Sci. (B) 13: 345- 359. 1941.