OCR A Level Biology:复习笔记2.5.5 Active Transport
Active Transport Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiratio...
OCR A Level Biology:复习笔记2.5.4 Practical: Investigating the Rate of Diffusion
Practical: Investigating the Rate of Diffusion It is possible to investigate the effect of certain factors on the rate of diffusion Different apparatus can be used to do this, such as Visking tubin...
OCR A Level Biology:复习笔记2.5.3 Diffusion & Facilitated Diffusion
Diffusion & Facilitated Diffusion Diffusion is a type of transportation that occurs across the cell membrane It can be defined as: The net movement, as a result of the random motion of its mole...
OCR A Level Biology:复习笔记2.5.2 Membrane Structure & Permeability
Factors Affecting Membrane Structure & Permeability The permeability of cell membranes is affected by different factors or conditions, such as: Temperature Solvent concentration Temperat...
OCR A Level Biology:复习笔记2.5.1 The Cell Surface Membrane
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...
OCR A Level Biology:复习笔记2.4.9 Practical: Measuring Enzyme Activity
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...
OCR A Level Biology:复习笔记2.4.8 Coenzymes, Cofactors & Prosthetic Groups
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...
OCR A Level Biology:复习笔记2.4.7 Enzyme Activity: Enzyme Inhibitors
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...
OCR A Level Biology:复习笔记2.4.6 Enzyme Activity: Substrate Concentration
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...
