Other Types of Transport PPT Notes & Activity

Name ___________________________________ _____/_____/______ Period _____ Score: ______/15Protein channelsCorrected by _______________________________________Other Types of Transport PPT Notes & ActivityCells function similarly in all living organisms.Diffusion and osmosis do not require ____________ from thecell. This is because the molecules move with a concentrationdifference (from higher to lower). ____________ molecules likesugars, starches, and proteins sometimes diffuse through__________ ____________. Because the molecules movefrom greater to lesser concentration through the channels, thisprocess also does not require energy.Active transportSometimes a cell needs to move molecules ____________ a concentration difference (from lower tohigher concentration). Active transport is a process that allows molecules to move across the cellmembrane from lower to higher concentrations. Active transport requires energy. ____________molecules act as “pumps” to move the molecules across the cell membrane. Your ____________ cellshave lots of protein pumps to move ions across the cell membrane. This is how signals travel through yournervous system.Other types of active transportA cell can take in larger particles of food by“____________” them. The cell membrane forms apocket around the particle. Once inside the cell, thepocket breaks loose from the cell membrane. It forms a____________ within the cytoplasm. Cells also sendmaterial out of the cell in the same way. When thishappens, a vacuole ____________ with the cellmembrane and the contents are forced outside of thecell. Both of these processes are types of active transportbecause they require energy.

Why are cells so small?One characteristic of cells is that they are very ____________. Why? The answer has to do with thecell membrane. Everything the cell needs to take in or has to get rid of has to go through the cellmembrane. Therefore the cell membrane needs to have a large ____________ _________ inrelation to the ____________ of the cell.The surface area-to-volume ratio is the area of the cell’s outer surface in relationship to itsvolume.Volume: Volume (cm 3 ) is the __________ inside an object. Sothe volume of a cube with 2 cm sides is 2 X 2 X 2 = 8Surface: Surface (cm 2 ) is the _____________ of an object. Acube has 6 sides, so its surface area is 2(2x2) + 2(2x2) + 2(2x2) =24As a cell gets bigger, so does its surface area. However, the volume of a cell increases at a____________ rate than the surface area of its cell membrane. If a cell gets too large, its cellmembrane will not have enough ____________ to meet the demands of its volume. This limits the____________ of cells. One way to increase surface area is to make the cell ____________ and____________ or skinny and flat. The nerve cells in your body are very long and thin.------------------------------------------------------------------------------------------Cell Membrane Transport Activity (10 points)DEMONSTRATE an understanding of the movement of molecules across a cell membrane.Materials:four candies 2 twist ties 1 plastic shopping bag a pair of scissorsProcedure: Your task is to get four candies into a plastic shopping bag. Sounds pretty easy, but here area few rules that you must follow that make the task a little more of a challenge.Rules:1. The four candies MUST enter the bag at the same time.2. The four candies MUST enter through the solid part of the bag (NOT the opening at the top).3. The internal environment of the bag must not be exposed to the external environment.4. When the candy finally enters the bag it must remain together in the form of a cluster.5. Do NOT eat the candy until you have completed the task and shown the solution toyour teacher.6. Do NOT discuss any part of this activity with any other groups in the class.7. Failure to follow any of these rules will result in a zero for this activity.Teacher’s Initials _______________