Biochemistry 4.1 - Enzymes as Catalysts PDF

Enzymes are CatalystsIntroductionUnit 1 discusses amino acids, the building blocks of proteins; their assembly into polypeptides; and some protein functions, such as ligand binding and ion transport across membranes. One of the most important functions of proteins is to serve as biological catalysts...

Enzymes are CatalystsIntroductionUnit 1 discusses amino acids, the building blocks of proteins; their assembly into polypeptides; and some protein functions, such as ligand binding and ion transport across membranes. One of the most important functions of proteins is to serve as biological catalysts, increasing the rate of the chemical reactions necessary for life. Although other macromolecules, especially RNA (see Chapter 8), can also act as biological catalysts, most biological catalysts fall into a large class of proteins called enzymes. This lesson explores the catalytic properties of enzymes.4.1.01 Enzymes Increase Reaction RateAs discussed in General Chemistry Chapter 3, chemical reactions are considered if they tend to proceed in the forward direction and equilibrium lies toward the products. However, spontaneous reactions do not necessarily proceed at a biologically relevant rate. For example, Concept 2.1.02 describes the hydrolysis of peptide bonds, which is a highly exergonic (ie, spontaneous, ∆G \