CIE A Level Biology复习笔记3.2.2 Rate: pH
Rate: pH All enzymes have an optimum pH or a pH at which they operate best Enzymes are denatured at extremes of pH Hydrogen and ionic bonds hold the tertiary structure of the protein (ie. the enzym...
CIE A Level Biology复习笔记3.2.1 Rate: Temperature
Rate: Temperature Enzymes have a specific optimum temperature – the temperature at which they catalyse a reaction at the maximum rate Lower temperatures either prevent reactions from proceeding or ...
CIE A Level Biology复习笔记3.1.5 Colorimetry
Colorimetry to Measure Enzyme Activity A colorimeter is able to measure light absorbance (how much light is absorbed) or light transmission (how much light passes through) a substance Colorimetry c...
CIE A Level Biology复习笔记3.1.4 Measuring Enzyme Activity
Measuring Enzyme Activity The progress of enzyme-catalysed reactions can be investigated by: Measuring the rate of formation of a product using catalase Measuring the rate of disappearance of a sub...
CIE A Level Biology复习笔记3.1.3 How Enzymes Work
How Enzymes Work The lock-and-key hypothesis Enzymes are globular proteins This means their shape (as well as the shape of the active site of an enzyme) is determined by the complex tertiary struct...
CIE A Level Biology复习笔记3.1.2 Enzyme Action
Mode of Enzyme Action Enzymes have an active site where specific substrates bind forming an enzyme-substrate complex The active site of an enzyme has a specific shape to fit a specific substrate Ex...
CIE A Level Biology复习笔记3.1.1 Enzymes
Enzymes as Proteins Enzymes are biological catalysts ‘Biological’ because they function in living systems ‘Catalysts’ because they speed up the rate of chemical reactions without being used up or c...
CIE A Level Biology复习笔记2.4.2 The Role of Water in Living Organisms
Water Molecules: In Living Organisms Water has many essential roles in living organisms due to its properties: The polarity of water molecules The presence and number of hydrogen bonds between wate...
CIE A Level Biology复习笔记2.4.1 Water & the Hydrogen Bond
Water Molecules: Hydrogen Bonds Water is of great biological importance. It is the medium in which all metabolic reactions take place in cells. Between 70% to 95% of the mass of a cell is water As ...
