What is catalytic activity?

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Catalytic activity is the increase in the rate and energy of a chemical reaction by a substance that is not changed in the reaction. In biological systems, it is carried out by enzymes that are essential for normal life processes. By decreasing the energy needed to start a reaction, enzymatic pathways increase the rate at which cells perform essential chemical functions. Catalysis is controlled by the regulation of enzymes. Some of them involve changes in the structure of the enzyme, while others operate by altering the cellular environment in which catalytic activity takes place.

In general chemistry, catalytic activity or catalysis is any change – increase or decrease – in the rate of a reaction by an agent that is not chemically altered by the process. In industry, this can mean any number of agents used to increase the rate and yield of reactions, but in biochemistry, catalytic activity refers to the work of enzymes, the proteins found in all organisms that mediate most functions. cells, including metabolism. Few, if any, biological processes would occur at a rate sufficient to sustain life without enzyme catalysis.

Some reactions would not take place without the catalytic activity of enzymes. Normally, many molecules have an energy barrier to react together. Called the activation energy, this threshold must be overcome for chemical reactions to take place.

In some cases, a high activation energy threshold means that the reactants are unlikely to react on their own, or will do so at a slow rate. When enzymes temporarily bind to one or more reactants, the activation energy required is reduced and the rate of reaction accelerates. Enzymes can also inhibit the activation of other enzymes and slow down the process.

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Enzymatic activity often results in multi-step biochemical reactions, each of which depends on a different catalyst and depends on the product of the previous step. Physically, the catalytic activity of many different enzymes takes place in the same cell organelle, accelerating the rate of reaction as a result. Changes in pH and temperature can, to some extent, work synergistically to increase the rate of catalysis. Temperatures beyond a certain range can damage the protein structure of an enzyme, rendering it incapable of activity.

In biological systems, catalytic activity is regulated by several different mechanisms. Enzymes are usually made of inactive precursor proteins, and these become active only through the action of another enzyme or an environmental change, such as movement from inside the cell to outside. Feedback inhibition reduces catalysis when the product of one or more enzyme pathways accumulates in the cell, blocking further release or manufacture of the enzyme that catalyzed the initial reaction. Likewise, reduced amounts of the reaction products will increase enzyme production.

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