Introduction
Enzymes are proteins folded into intricate forms that are found all over the body. Enzymes catalyse (speed up) chemical reactions; in some cases, enzymes can make a chemical reaction millions of times faster than in normal circumstances.
The active site of an enzyme binds a substrate, which is then transformed into products. The enzyme is ready to bind to a new substrate and restart the activity after the products have left the active site.
Feedback inhibition (also known as End-product inhibition) is a type of negative feedback that can be used to control metabolic pathways.
- End-product inhibition occurs when a reaction’s final product blocks an enzyme from a previous phase in the sequence.
- The product interacts with an allosteric site on the enzyme, momentarily inactivating it (via non-competitive inhibition).
- The reaction sequence is paused, and the rate of product synthesis is reduced since the enzyme can no longer function.
Table of Contents
- Definition of Feedback Inhibition
- Process of Feedback Inhibition
- Function of Feedback Inhibition
- Examples of Feedback Inhibition of Enzymes
- Frequently Asked Questions – FAQs
Definition of Feedback Inhibition
In biology, feedback inhibition is defined as the mechanism by which the reaction’s end product inhibits or controls the enzyme’s function that helped make it. In other words, it refers to a circumstance in which the end products produced at the end of a series of reactions help to suppress the activity of the enzymes involved in the end product’s creation.
When a product develops in a cell beyond an adequate point, an enzyme involved in its synthesis is inhibited, reducing its production. The inhibition is relieved when the product has been used or broken down, lowering its concentration, and the product formation resumes. Feedback inhibition mechanisms limit the concentration of certain cell elements.
The steps made by the body to regulate some natural processes are known as feedback inhibition, and it is most commonly connected with turning enzymes on and off. We need to learn more about enzymes and their roles in the body before we can understand what purpose feedback inhibition serves and how it does its important task.
Enzymes, Substrates, and Products
Enzymes help in the acceleration of chemical reactions in the human body. They attach to molecules and alter them in specific ways. They are needed for digestion, breathing, muscle and nerve operation, and different other functions.
Enzymes are capable of catalysing reactions that keep us alive – our metabolism.
Enzymes accelerate (catalyse) chemical reactions; in some situations, enzymes can speed up a chemical reaction millions of times faster than it should be.
A substrate binds to an enzyme’s active site and is translated into products. The enzyme is ready to bind to a new substrate and restart the activity once the products leave the active site.
Process of Feedback Inhibition
Feedback inhibition is usually performed by an “allosteric site” on an enzyme, which alters the shape of enzyme and, as a result, the behaviour of the active site.
The end product binding to the allosteric site delays or prevents the enzyme’s activity, resulting in slight or no further end product being produced. The enzyme will encounter rarer particles of the end product as levels of the end product decrease, and its activity will improve again.
When more of a product is produced than the cell requires, feedback inhibition minimises waste. It can also protect the organism from harm when too much of the pathway’s end product is toxic to organisms.
Feedback inhibition permits organisms to modify their reaction rate, relying on how considerably their end product is required, preventing harmful levels of their end product from accumulating.
Function of Feedback Inhibition
The body uses feedback inhibition to prevent a variety of potentially harmful conditions, including:
- Depletion Prevention: In the absence of feedback inhibition, metabolic processes that don’t cease even when their final product isn’t needed could deplete raw materials and energy. The creation of ATP from glucose is a good instance of this. ATP inhibits the enzymes which create ATP from glucose by feedback inhibition. When the cell has lots of ATP, this protects glucose by preventing it from being broken down.
- Homeostasis Maintenance: The ability to maintain constant internal conditions in the face of changing environmental conditions is a vital aspect of existence. Feedback regulation regulates some chemical messengers that are aimed at maintaining homeostasis.
- Waste: In the absence of feedback inhibition, energy and raw resources that could be employed for critical cellular operations could be spent on non-essential ones.
- Prevents Harmful Accumulation: In large concentrations, the final products of various metabolic reactions can be harmful. Cholesterol is an outstanding example of something the body might produce that is beneficial in tiny amounts but harmful in high amounts.
Examples of Feedback Inhibition of Enzymes
Production of Cholesterol
Cholesterol production is controlled by feedback inhibition. Cholesterol is required to promote cell-to-cell communication and to keep cell membranes intact. However, too much cholesterol is harmful and can have disastrous repercussions.
As a result, it’s critical for the body to be able to minimise cholesterol production when our diets are high in cholesterol. Here’s when feedback inhibition helps a lot. When there is a lot of cholesterol in the blood, cholesterol synthesis is under feedback inhibition by cholesterol.
Regulation of ATP Synthesis
Our cells produce ATP (Adenosine triphosphate) from glucose through a series of biochemical processes. When the body produces too much ATP, it can lead to glucose depletion and energy loss. As a result, controlling the quantity of glucose broken down to make ATP is essential.
ATP allosterically regulates the first enzyme in the breakdown chain to control the quantity of glucose that is broken down to produce ATP. This enzyme would not break down any more glucose if ATP attaches to it.
Our bodies utilise their energy more efficiently this way, reserving it in the steady form of glucose until it is required.
Amino Acid Synthesis
Amino acids are “building blocks” of protein that the human body needs. However, various amino acids may be required by the cell at various periods. This means, similar to transforming glucose to ATP, cells must figure out how to make the most efficient use of their basic materials to produce precisely what they require at any given time. They utilise feedback regulation, just like ATP, to ensure that they only create the amino acids required at any particular time.
Related Links:
- What is an enzyme?
- What Is Competitive Inhibition?
- What Is An Example Of Competitive Inhibition?
- What Is The End Product Inhibition?
Frequently Asked Questions – FAQs
How would feedback inhibition stop a cascade?
The final product of a metabolic route works on the main enzyme regulating admission to that pathway, preventing more of the end by-product from being created through the process of feedback inhibition.
Is feedback inhibition competitive or non-competitive?
Feedback inhibition is an essential biochemical procedure that makes use of noncompetitive inhibitors to regulate some enzyme reactions. The final product in this process blocks the enzyme that catalyses the first reaction in a series. The synthesis of several amino acids is regulated by feedback inhibition.
Where is feedback inhibition commonly found?
Feedback inhibition is commonly achieved by using an “allosteric site,” which is a location on an enzyme that affects the shape of the enzyme and thus the behaviour of the active site.
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