{"id":395,"date":"2018-09-04T13:06:09","date_gmt":"2018-09-04T17:06:09","guid":{"rendered":"https:\/\/wp.geneseo.edu\/ibis-curriculum\/?p=395"},"modified":"2018-11-02T12:21:09","modified_gmt":"2018-11-02T16:21:09","slug":"gradients-and-membrane-transport","status":"publish","type":"post","link":"https:\/\/wp.geneseo.edu\/ibis-curriculum\/gradients-and-membrane-transport\/","title":{"rendered":"Gradients and Membrane Transport"},"content":{"rendered":"

Outcomes: \u00a0<\/b>Gradients 2, Gradients 3, Gradients 4; Membrane Transport 2, Membrane Transport 3, Membrane Transport 4, Membrane Transport 5; Thermoregulation 7<\/p>\n

Prerequisite objective: \u00a0<\/b>Membrane Transport 1<\/p>\n

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  1. Ask students to work in groups to complete a table to compare and contrast modes of transport. (Membrane Transport 2)<\/span><\/li>\n<\/ol>\n\n\n\n\n\n
    <\/td>\nDiffusion<\/span><\/td>\nFacilitated diffusion<\/span><\/td>\nActive transport<\/span><\/td>\n<\/tr>\n
    Description<\/span><\/td>\nPassive movement of…<\/span><\/td>\nPassive movement of…<\/span><\/td>\nActive movement of…<\/span><\/td>\n<\/tr>\n
    Are proteins involved? (yes\/no)<\/span><\/td>\nNo<\/span><\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Follow up with clicker questions on how gradients relate to membrane transport. (Gradients 3, Gradients 4, Membrane Transport 3, Membrane Transport 5)<\/span><\/p>\n

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    1. (Gradients 4, Membrane Transport 5) Show an <\/span>image<\/span><\/a> of the activity at a cell membrane, that demonstrates that there are lots of materials moving in and out of cells (see example below). Ask students to brainstorm for 3 minutes about factors that can affect how quickly this transport occurs. In our experience, the list often contains factors such as: \u00a0temperature, membrane permeability, size of chemical gradient, and sometimes cell shape. Formalize the role of cell shape with the concept of surface area-to-volume ratio. Most cells are very small to maintain high SA\/V, facilitating an optimal rate of material movement. Learn.Genetics has a great demonstration of cell size and scale <\/span>here.<\/span><\/a> Students may or may not have identified temperature as a factor with enzymes in mind. This is also a good opportunity to address Thermoregulation 7: \u00a0enzymes work best at a narrow temperature range.<\/span><\/li>\n<\/ol>\n