Catalyst (chemistry)
A catalyst in chemistry is a substance that accelerates chemical reactions by lowering the required activation energy without being consumed in the process. Catalysts play a crucial role in various chemical processes by facilitating the breaking and forming of chemical bonds, enabling reactions to occur more quickly and efficiently. The concept of catalysts was first theorized by Swedish chemist J.J. Berzelius in 1835, who proposed that some external force influenced certain reactions. While catalysts have been utilized in various crafting techniques historically, their scientific understanding developed over time.
Most catalysts are selective, meaning they only work with specific sets of molecules, often featuring grooves that allow only compatible molecules to fit and react. Enzymes, a type of naturally occurring catalyst found in the human body, exemplify this process. They consist of proteins and non-proteins that create an active site, attracting and facilitating the collision of substrate molecules, thus reducing the energy barrier for reactions. Enzymes are essential for numerous biological processes, including digestion, and deficiencies in specific enzymes can lead to significant health issues. Overall, catalysts are vital in both industrial applications and biological systems, enabling reactions that are fundamental to life and various chemical industries.
Subject Terms
Catalyst (chemistry)
Catalysts are substances that speed up chemical reactions. They assist in changing chemical bonds by reducing the amount of energy required for chemical bonds to break and reform. After a chemical reaction takes place, the catalyst remains unchanged. It can continue to accelerate reactions for an extended period of time.
Discovery of Catalysts
Catalysts were first theorized by the Swedish chemist J.J. Berzelius. During his studies of chemical changes in 1835, he realized that certain reactions in the body happened in a manner that conflicted the understanding of the time about the chemicals involved. In these circumstances, he theorized that some undiscovered outside force was acting on the chemicals. He named this theoretical energy "catalytic force."
Catalysts had already been used for various crafting purposes. For example, various catalysts were used to heat metal, and yeast was used to create alcohol. However, the crafters did not understand why adding these materials caused faster reactions; they simply observed the results. Soon after Berzelius's work was published, scientists discovered that these objects were catalysts.
How Catalysts Function
In order for chemical bonds to be broken, a specific amount of energy needs to be imbued into the chemical. The formation of chemical bonds also requires a specific amount of energy. The energy required to form or break a chemical bond is called the activation energy. The activation energy required for a chemical reaction depends on the chemicals involved. However, in many cases, the amount of energy required to form or break a chemical bond is very high. Because of this, many chemical reactions take an extended period of time to occur naturally.
Catalysts help chemicals combine, reducing the amount of activation energy required to begin a chemical reaction. Most catalysts only work with a specific set of molecules. They contain grooves into which the molecules fit perfectly, encouraging them to bond together. Other molecules will not fit into the groove, so they will not be encouraged to bond. In rare cases, multiple molecules will fit into a single catalyst.
One common example of a naturally occurring catalyst is the enzyme. Enzymes are catalysts that exist within the human body. They are made up of a single globular protein and a paired non-protein. Together, these parts create a globe with an active site. The active site is incredibly attractive to two types of chemicals, drawing them together and forcing them to collide. By forcing them to collide, the enzyme drastically lowers the active energy required for the reaction. The enzyme then releases the reacting molecule, called the substrate. Because the substrate fails to change the enzyme during its chemical reaction, the enzyme is free to continue assisting in additional chemical reactions.
Enzymes are very common in the human body and help organic molecules, such as vitamins, engage in beneficial chemical reactions. They also help with digestion. If a person is lacking specific enzymes, he or she may have serious health problems.
Bibliography
"Enzymes." BBC, 2023, www.bbc.co.uk/schools/gcsebitesize/science/add‗edexcel/cells/enzymesrev1.shtml. Accessed 3 Jan. 2023.
Castro, Joseph. "How Do Enzymes Work?" LiveScience, Purch, 26 Apr. 2014, www.livescience.com/45145-how-do-enzymes-work.html. Accessed 2 Nov. 2016.
"Catalysts Speed It Up." Chem4Kids, Andrew Rader Studios, 2016, www.chem4kids.com/files/react‗catalyst.html. Accessed 2 Nov. 2016.
"The Central Role of Enzymes as Biological Catalysts." NCBI, Sinauer Associates, 2000. www.ncbi.nlm.nih.gov/books/NBK9921. Accessed 2 Nov. 2016.
"Definition of Catalyst." Chemicool, Chemicool, 2016, www.chemicool.com/definition/catalyst.html. Accessed 2 Nov. 2016.
"OE Explains...Catalysts." U.S. Department of Energy, www.energy.gov/science/doe-explainscatalysts. Accessed 3 Jan. 2023.
"How Digestion Works." EnzymeStuff, Enzyme Stuff, 2005. www.enzymestuff.com/digestion.htmAccessed 2 Nov. 2016.
"Role of Enzymes in Biochemical Reactions." Elmhurst College, Elmurst College, 2003. www.chemistry.elmhurst.edu/vchembook/570enzymes.html. Accessed 2 Nov. 2016.