Factors Affecting Membrane Structure & Permeability The permeability of cell membranes is affected by different factors or conditions, such as: Temperature Solvent concentration Temperat...
CIE IGCSE Biology: 复习笔记：5.1.5 Enzymes & pH: Extended Enzymes & pH: Extended The optimum pH for most enzymes is 7 but some that are produced in acidic conditions, such as the stomach, h...
Roles of Membranes Membranes are vital structures found in all cells The cell surface membrane creates an enclosed space separating the internal cell environment from the external environment Intra...
Practical: Measuring Enzyme Activity The progress of enzyme-catalysed reactions can be investigated by: Measuring the rate of formation of a product Measuring the rate of disappearance of a substra...
Coenzymes, Cofactors & Prosthetic Groups There are substances other than substrates and inhibitors that interact with enzymes Some enzymes can only function properly if another non-protein subs...
Enzyme Inhibitors Reversible inhibitors An enzyme's activity can be reduced or stopped, temporarily, by a reversible inhibitor There are two types of reversible inhibitors: Competitive inhibitors h...
Enzyme Activity: Substrate Concentration The greater the substrate concentration, the higher the rate of reaction: As the number of substrate molecules increases, the likelihood of enzyme-substrate...
Enzyme Activity: Enzyme Concentration Enzyme concentration affects the rate of reaction The higher the enzyme concentration in a reaction mixture, the greater the number of active sites available a...
Enzyme Activity: Temperature Enzymes have a specific optimum temperature This is the temperature at which they catalyse a reaction at the maximum rate Lower temperatures either prevent react...
