OCR A Level Biology:复习笔记2.5.7 Osmosis
Osmosis All cells are surrounded by a cell membrane which is partially permeable Water can move in and out of cells by osmosis Osmosis is the diffusion of water molecules from a dilute solution to ...
OCR A Level Biology:复习笔记2.5.6 Endocytosis & Exocytosis
Endocytosis & Exocytosis The processes of diffusion, osmosis and active transport are responsible for the transport of individual molecules or ions across cell membranes However, the bulk trans...
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...
