What action does an enzyme perform that increases the rate of a biological reaction?

An isotonic solution is a solution with the same concentration of solutes as the cytoplasm of cells. When cells are placed in an isotonic solution, there is no net movement of water across the cell membrane, and the cells maintain their normal shape and volume. Isotonic solutions are commonly used in medical settings for intravenous (IV) fluid therapy and to prepare medications for injection. Injecting isotonic solutions into tissues or the circulatory system helps prevent cells from experiencing osmotic imbalances that could lead to cell shrinkage (crenation) or swelling (lysis). Examples of isotonic solutions used in medicine include normal saline (0.9% NaCl) and Lactated Ringer's solution, which closely match the osmolarity of bodily fluids and are well-tolerated by cells. Isotonic solutions are also used in laboratory settings for cell culture and to maintain the osmotic balance of cells during experimental procedures. Overall, isotonic solutions play a crucial role in maintaining cellular homeostasis and preventing damage to cells exposed to external fluids or medications.

Epithelial tissue covers the outside of the body and lines the surfaces of organs and cavities within the body. It forms protective barriers that shield underlying tissues from mechanical injury, pathogens, and chemical damage. Epithelial cells are closely packed and arranged in continuous sheets, providing a barrier against the external environment and regulating the exchange of substances between different compartments. Epithelial tissue can be found in various forms, including simple epithelium (single layer of cells), stratified epithelium (multiple layers of cells), squamous epithelium (thin, flat cells), cuboidal epithelium (cube-shaped cells), and columnar epithelium (elongated cells). Depending on its location and function, epithelial tissue may have specialized features such as cilia, microvilli, or keratinization. Epithelial tissue is essential for maintaining homeostasis, protecting against pathogens, absorbing nutrients, and facilitating the exchange of gases and fluids in the body.

In the taxonomic hierarchy, the family represents a higher-level grouping that includes related genera. In the classification provided, Elephantidae represents the family, encompassing all elephants. The specific epithet "indicus" refers to the Indian elephant, which is a subspecies of the Asian elephant.

Enzymes are biological catalysts that increase the rate of chemical reactions by lowering the activation energy required for the reaction to occur. Activation energy is the energy barrier that must be overcome for a chemical reaction to proceed, representing the energy required to break bonds in the reactant molecules and initiate the formation of new bonds in the product molecules. Enzymes facilitate chemical reactions by binding to specific substrates (reactant molecules) at their active sites, forming enzyme-substrate complexes. The active site of an enzyme is a region with a specific three-dimensional structure that complements the shape and chemical properties of the substrate, allowing for precise substrate recognition and binding. Once bound to the active site, the enzyme catalyzes the conversion of substrates into products by stabilizing transition states and facilitating bond rearrangements. By providing an alternative reaction pathway with a lower activation energy, enzymes accelerate the rate of reactions without being consumed or permanently altered in the process. This enables enzymes to catalyze multiple rounds of substrate conversion, making them highly efficient and specific catalysts essential for numerous biological processes.