Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
Enzymes are specific to particular reactions and act as important catalysts in many biological reactions, including those involved in digestion and respiration. Evidence for the existence and action of enzymes initially arose from Louis Pasteur’s study of fermentation of sugar to form alcohol in the nineteenth century. Further work, involving a wide range of scientists, proposed that enzyme action was associated with protein molecules (ACSCH049). Catalysts work in a variety of ways, and knowledge of the structure of enzyme molecules helps scientists to explain and predict how they are able to lower the activation energy for reactions (ACSCH053). This work often relies on evidence from laboratory experiments as well as analytical methods used to determine the structure of molecules (ACSCH049). For example, Australian John Cornforth was awarded the Nobel Prize for chemistry for his study of the molecular geometry of enzymes and how they are able to catalyse essential biochemical reactions.
Corrosion of metals can have significant negative economic, environmental and safety consequences. For example, corrosion of steel pipes led to the 2008 gas plant explosion on Varunus Island, Western Australia, cutting the state’s gas supply by 30%. Many heritage structures, particularly bridges, have significant corrosion issues that compromise user safety, such as corrosion of main cables on suspension bridges. Addressing these issues can be complex and costly, and decisions about maintenance or replacement often involve consideration of factors such as cost, aesthetic or cultural value, and safety (ACSCH052). Most contemporary methods of corrosion prevention rely on knowledge of chemical and electrochemical redox processes, including the use of grapheme within varnish coatings of iron or steel. The extension of a metal’s useful life will achieve cost savings and improve environmental impacts for many Australian industries, where a significant amount of industry is located on the coast and/or relies on shipping for imports and exports (ACSCH054).
Collision theory enables chemists to explain and predict the rates of a vast range of chemical reactions in many different contexts (ACSCH053). German chemist Max Trautz published research about aspects of collision theory, in particular the significance of activation energy, in 1916. William Lewis, working independently in England at the same time, proposed complimentary work on collision theory in 1918 (ACSCH048). The First World War prevented not only the two chemists working together, but even being aware of each other’s work. Further work on collision theory enabled a quantitative approach to be taken which allowed for the prediction and control of chemical reaction rates; these understandings are now used by chemical engineers to design efficient, safe and economically viable industrial processes (ACSCH052).