by means of a chemical equation, show how the body rids itself of the major end-products of metabolism. Please explain.
The major end-products of metabolism in the human body are carbon dioxide (CO2), water (H2O), and various nitrogenous waste compounds, such as urea. The process by which the body eliminates these waste products is called excretion. Let's break down each waste product and explain how the body gets rid of them:
1. Carbon dioxide (CO2):
During cellular respiration, glucose and oxygen are metabolized in the body's cells to produce energy in the form of adenosine triphosphate (ATP). As a result of this process, carbon dioxide is produced as a waste product. Most of the carbon dioxide in the body combines with water to form carbonic acid (H2CO3) through an enzyme called carbonic anhydrase. The chemical equation for this reaction is:
CO2 + H2O ⇌ H2CO3
The carbonic acid then dissociates into bicarbonate ions (HCO3-) and hydrogen ions (H+). The bicarbonate ions can move across cell membranes and enter the bloodstream. In the lungs, the reverse reaction occurs, and carbon dioxide is formed again. The lungs eliminate the majority of carbon dioxide from the body by exhaling it as a waste product.
2. Water (H2O):
Water is a byproduct of various metabolic processes in the body, such as cellular respiration and the breakdown of macronutrients. The body eliminates water through various means, including sweating, urinating (urine production), and through respiration (moisture in exhaled breath). However, it is important to note that the human body also needs to maintain a proper water balance to function optimally, so not all water is eliminated as waste.
3. Nitrogenous waste compounds:
Nitrogenous waste compounds are produced from the breakdown of proteins in the body. One of the primary waste products is urea, which is formed in the liver. Urea is highly soluble in water and can be eliminated by the kidneys through urine. The chemical equation for the formation of urea is as follows:
NH3 + CO2 → NH2CONH2
In this reaction, ammonia (NH3) combines with carbon dioxide (CO2) to form urea (NH2CONH2).
Other nitrogenous waste compounds, such as uric acid, are eliminated through the kidneys as well, and some are excreted as a component of sweat.
In summary, the body eliminates the major end-products of metabolism by exhaling carbon dioxide, excreting water through sweat and urine, and excreting nitrogenous waste compounds, primarily urea through urine. The chemical equations provided illustrate the formation of these waste products and their subsequent elimination.