Metabolic Pathway Essay

A metabolic pathway is a series of chemical reactions in a cell that build up and breakdown molecules for cellular processes. It is a step by step process of interconnected biochemical reactions that convert a substrate molecule(s) through a series of metabolic intermediates, finally creating a final product, Boundless, (2017). For example the process that builds larger carbohydrate molecules into glucose is known as an anabolic process as it requires energy. This high energy demand is obtained by ATP and high energy molecules like NAD and NADH (nicotinamide adenine dinucleotide).The catabolic reaction is the breaking down of molecules and produces energy, for example turning glucose into larger carbohydrates. It degrades the molecule into

They are biological catalysts, which means that they can control and speed up chemical reactions in the body, without them these reactions would rarely take place. They are a type of protein that have been folded into complex shapes to allow other smaller molecules (substrate molecules - see appendix 1) to fit into them (just like a lock and key - see appendix 1). The enzyme is the lock and substrate is the key, so only the correctly sized key (substrate) will fit into the keyhole (active site) and the lock (enzyme), any keys that are bigger, smaller or have different teeth will not fit the keyhole or lock as only only the correct key will open the lock. These smaller molecules can also join together to make larger ones, allowing them to fit into the space they are joining (these are called product molecules - see appendix 1). The place that these substrate molecules fit is called the active site, so if the enzyme then changes shape the active site may no longer work meaning the enzyme has now been denatured. “Following the formation of an enzyme- substrate complex, the substrate molecule undergoes a chemical reaction and is converted into a new product” Oxford University Press