Quantitative changes

The quantitative changes in the availability of the active biomolecules occur in order to compensate for the loss of efficiency of the system caused by the stress. This is illustrated by the following examples.

1. There is an increase in the amount of ribulose bisphosphate carboxylase in plants exposed to bright light than those in shade. As you can correlate, there should be an increase in the level of this enzyme to make use of the extra reducing power, (NADPH) generated due to high light intensity.
2. During infection, enhanced synthesis of hydrolytic enzymes for destroying the invader, and synthesis of inhibitors by host that work against the damaging enzymes produced by the invaders has been observed.
3. In halotolerant species there is an increase in the synthesis of certain amino acids in order to keep the osmotic balance.
4. To protect against injury due to toxic metal, there is enhanced synthesis of chelating molecules to avoid toxic ions.