Cohesion-tension model (Edexcel A-level Biology B)

Topic 4: Exchange and transport (Edexcel A-level Biology B)

The wide variety of tasks that are written into the 18 lesson PowerPoints and accompanying resources that are included in this lesson bundle will engage and motivate the students whilst covering the detailed content of topic 4 of the Edexcel A-level Biology B specification (Exchange and transport). The following specification points are covered by these lessons: * Understand how the surface area to volume ratio affects the transport of molecules in living organisms * Understand why organisms need a mass transport system and specialised gas exchange surfaces as they increase in size * The structure of the cell surface membrane * Passive transport is brought about by diffusion and facilitated diffusion * Passive transport is brought about by osmosis * Understand how the properties of molecules affects how they are transported * Large molecules are transported in and out of cells by endocytosis and exocytosis * The process of active transport * The phosphorylation and hydrolysis of ATP * Understand how insects, fish and mammals are adapted for gas exchange * The structure of the heart, arteries, veins and capillaries * The advantages of the double circulatory system * The sequence of events of the cardiac cycle * The myogenic stimulation of the heart * Interpreting ECG traces * The role of platelets and plasma proteins in the sequence of events leading to blood clotting * The structure of haemoglobin in relation to its role in the transport of respiratory gases * The Bohr effect * The dissociation curve of haemoglobin * The significance of the oxygen affinity of foetal haemoglobin * The similarities and differences between the structure and function of haemoglobin and myoglobin * The formation and reabsorption of tissue fluid * Know that tissue fluid that is not reabsorbed is returned to the blood via the lymph * The structure of the xylem and phloem in relation to their role in transport * The movement of water by the apoplastic and symplastic pathways * The cohesion-tension model Hours and hours has gone into the intricate planning of all of these lessons and the quality can be sampled by downloading the following lessons which have been uploaded for free: Surface area to volume ratio ATP, active transport, endocytosis and exocytosis Structure of the heart, arteries, veins and capillaries Double circulatory system Apoplastic and symplastic pathways