澳洲AMC考试2022即将开赛，抓紧时间备赛！
相较于美国AMC，澳洲数学学术活动（澳洲AMC）对初次参加考试或者比赛的新生比较友好，澳洲3年级的小朋友就可以参加学术活动。澳洲AMC考试2022即将开赛！今天不如就让我们一起来了解一下这项风靡全球的数学国际学...
CIE A Level Biology复习笔记3.2.6 Vmax & the Michaelis-Menten Constant
Vmax & the Michaelis-Menten Constant Substrate concentration affects the rate of catalysis in an enzyme-substrate reaction When the substrate concentration is fixed (and enzyme concentration is...
CIE A Level Biology复习笔记3.2.5 Rate: Inhibitor Concentration
Rate: Inhibitor Concentration There are two types of inhibitors: Competitive inhibitors have a similar shape to that of the substrate molecules and therefore compete with the substrate for the acti...
CIE A Level Biology复习笔记3.2.3 Rate: Enzyme Concentration
Rate: 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 and the grea...
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...
