MICRONUTRIENTS - THE ROLE OF THE ENZYMES - THE ROLE OF ENZYMES IN THE MACHINERY OF METABOLISM

 

6

The growth cycle of the plant begins shortly after the seed is placed in the ground. Small protein clusters called enzymes in the germ cells of the seed are activated. The important life-giving feature of an enzyme is its ability to speed up the rate of a specific chemical reaction in the plant, thus promoting rapid growth. Each individual enzyme is tied in to one chemical reaction.

The necessary enzymes continue to be produced in each cell at the time of cell division…throughout the life of the plant. Each protein cluster is designed to carry on its particular task during plant growth. As the plant enters the fruiting stage, the blueprints for establishing the next cycle of enzymes are laid down in the genes of the seed. Finally, a few enzymes that will initiate growth in the seed are located under the seed coat, and all is in readiness for the next growth cycle.

 

Enzymes Need Micronutrients

Each compact protein cluster, or enzyme, is inert and non-specific until activated by a specific metal ion. The metal ion acts as the catalyst that activates the enzyme and funtions as an integral part of the enzyme…which only then can begin its work in the metabolic process.

These metal activators, or enzyme keys, are the micronutrients.

 

The Enzyme Cycle

Each protein bundle or enzyme, activated by its micronutrient, attacks its specific work load – a storehouse of chemical material to be transformed into compounds needed for plant growth and structure. Each storehouse of material is called a substrate. The enzyme and substrate momentarily form a complex chemical in which the enzyme becomes the active transporter and changer of the substrate.

Upon delivery of the new product, the enzyme re-establishes itself and returns to the substrate to begin the cycle all over again.

 

Enzymes Lower Energy Barriers

Enzymes break down the energy barriers in the plant's internal chemical reactions by supplying substrates with high energy. Enzymes regulate the total amount of both substrate and growth product in the plant. Without enzymes, the substrate would build up against the energy barrier and growth would slow down. But with active enzymes a constant flow of growth substances is assured.

All of life and growth depends upon these little "organic-metal" molecules that perform feats out of all proportion to their size.

In the next unit, we will look closely at the specific activity of a few of these enzymes, noting especially the role of each of the micronutrients as a key activator of an enzyme.

The plant, through photosynthesis, fixes carbon dioxide and water in the form of sugars. The sugars are used in respiration to provide energy – breaking down again to carbon dioxide and water. Some sugars are synthesized into amino acids and finally proteins, the building blocks of living tissue. But the system doesn't work without enzymes and their co-workers, the micronutrients.

Next Page