There are different kinds of reactions that take place. Now we will discuss about the different reactions that takes place in the human body. This deals with the various kinds of metabolic reactions that take place in our human body that reduces the calories and fats. Thus when the human body requires calories, we intake few calories that turns into fat in order to produce energy. This conversion of energy from the fat cells to produce energy thro' different reactions is biologically referred to as triglycerides.

Metabolism is the process of converting the food into energy by the human body by undergoing different reactions. There are various series of steps that are involved in this metabolic process. The triglycerides are first broken down into various components like glycerol and fatty acids. These components are then absorbed by the liver, muscles and kidneys. Then chemically different reactions take place which breaks up these components further that would produce energy for the human body.
But when the above said different reactions take place, they produce heat along with the reactions that gives the maximum temperature. Also some waste products such as water and carbon dioxide are also produced as a result of these chemical reactions. This water is excreted by the human body by means of urine and sweat and the carbon dioxide is exhaled in the air from the thro' nose. There are number of calories that are burnt every day by our human body by these different reactions and it is called as energy expenditure.
Next we discuss about different reactions that are caused by the allergies in different people. To define, Allergy is a condition in which a child is extra sensitive to some of substances which are innocuous or some triggers like dust or pollution. But these allergies that produce different reactions do not harm a normal person. Certainly, some of the children are predisposed to some allergies. For example, some children can hug the cat with ease and comfort whereas some of the children gets into relentless sneezing.

There are large numbers of substances available that cause allergies which results in different reactions and these substances are called allergens. These substances are mostly air-borne or food based. The same allergens or substances can also cause different reactions in different people. For example, dust in house can sometimes irritate mucus lining of the respiratory tract of one person, while it could irritate the conjunctiva of the eye of some other person.

The different reactions that are handled in terms case of chemical and crop protection industries are Benzoin reaction, condensation reaction, friedel craft reaction, Fries Rearrangement reaction, Gattermann Aldehyde Synthesis, Heck reaction, Knoevenagal Condensation, Mannich reaction, Rosenmund reaction, Sandmeyer reaction, Skraup and Ullman reaction, Vilsmeier Haack and Wittig reaction. These different reactions are utilized in order to produce various chemicals that required for protecting the crops.

There are different reactions that the people experience in their life. They are as follows. i) Allergic reactions like sneezing, coughing, watery eyes, itchy eyes, nose or throat. ii) Asthma which causes sudden attack of labored breathing and chest constriction. iii) Infections like localized skin or mucosal infections. iv) Irritation such as burning eyes, nasal congestion, coughing etc.