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Cotyledons Experiment

I need some help on the Induction of nitrate reductase by NO3- in radish seedling cotyledons:
20 pairs of cotyledons are incubated for 4 hours with different solutions,

Solution A: K2SO4, MgSO4, Ca(H2PO4)
Solution B: K2SO4, MgSO4, Ca(H2PO4), KNO3
Solution C: K2SO4, MgSO4, Ca(H2PO4), KNO3, cycloheximide
Solution D: K2SO4, MgSO4, Ca(H2PO4), KNO3, cycloheximide, chloramphenicol

The cotyledon extract was used to perform NR enzyme activity assay.
The following results were produced:

No incubation medium at zero time: 0.222 absorbance at 540nm
4hours incubation with-
Sol. A- 0.117 absorbance at 540nm
Sol B-0.209 absorbance at 540nm
Sol C-0.036 absorbance at 540nm
Sol D-0.362 absorbance at 540nm

Solution Preview

Explanation of de novo synthesis upon gene induction by exogenous nitrate
Induction of nitrate reductase by NO3- in radish seedling cotyledons:
20 pairs of cotyledons are incubated for 4 hours with different solutions,
Solution A: K2SO4, MgSO4, Ca(H2PO4)
Solution B: K2SO4, MgSO4, Ca(H2PO4), KNO3
Solution C: K2SO4, MgSO4, Ca(H2PO4), KNO3, cycloheximide
Solution D: K2SO4, MgSO4, Ca(H2PO4), KNO3, cycloheximide, chloramphenicol
The cotyledon extract was used to perform NR enzyme activity assay.
The following results were produced:
No incubation medium at zero time: 0.222 absorbance at 540nm - This is a control
4hours incubation with-
Sol. A- 0.117 absorbance at 540nm
Sol B-0.209 absorbance at 540nm
Sol C-0.036 absorbance at 540nm
Sol D-0.362 absorbance at 540nm

In this experiment, you are assaying for the activity of the enzyme nitrate reductase in radish seedling cotyledons. All plants must obtain their nitrogen requirement from the soil as nitrates. The nitrate is converted into proteins and nucleotide that the plant need. The nitrate reduction reaction that converts nitrogen to nitrate is a two-step enzyme catalyzed ...

Solution Summary

This solution looks at the nitrate reduction reaction that converts nitrogen to nitrate in a two step enzyme catalyzed reaction. This reaction mechanism is detailed in a step-by-step method. All references used are included.

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