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Answer in comp book…. The process by which water passes into or out of a cell is called? The dispersal of ink in a beaker of water is an example of? Ion channels serve as: Passageways Information receivers Cell identifiers Food molecules.
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Answer in comp book… • The process by which water passes into or out of a cell is called? • The dispersal of ink in a beaker of water is an example of? • Ion channels serve as: • Passageways • Information receivers • Cell identifiers • Food molecules 4. Diffusion takes place from an area of _______ concentration to an area of __________ concentration. 5. A calcium ion channel will allow: • Only calcium ions to pass • Any kind of ion to pass • Positive ions to pass • None of the above
Active Transport Chapter 5 Section 2
Active Transport • Movement of contents up their concentration gradient. • Movement from lower concentration to a higher concentration • Requires energy
Cell Membrane Pumps • Remember Ion Channels and Carrier Proteins?? • These proteins are used in passive transport, but can also be used in active transport. • Called “pumps” because they move substances from lower to higher concentration. • Similar to proteins in facilitated diffusion except use energy.
Sodium-Potassium Pump • Some cells must have a higher concentration of sodium outside the cell and higher concentration of potassium inside the cell. • P. 104
Quick… The sodium-potassium pump usually pumps. • Sodium into the cell • Potassium into the cell • Only a potassium and sugar molecule together. • Potassium out of the cell.
Movement in Vesicles • When molecules are too large to pass through the cell membrane through the previously discussed transport. • Endocytosis vs. Exocytosis
Endocytosis • Where cells ingest external substances. • Cell membrane surrounds substances and pinches off to move to the inside of the cells. • Types of endocytosis: • Pinocytosis: movement of solutes or fluids • Phagocytosis: movement of larger particles or whole cells. (many unicellular organisms feed via phagocytosiswhile animals may use it to ingest harmful substances)
Exocytosis • Process where substances are expelled from inside the cell to the • Reverse of endocytosis • Used to release: larger molecules: proteins, waste products, or toxins.