To discuss:
Simple diffusion, factors that determine its speed, and examples of its physiological and clinical relevance.
Introduction:
Cells are regarded as the simplest unit (structural and functional) of life. Cellular membrane, nucleus, and cytoplasm are the three major components of a cell. Cellular membrane, which surrounds the entire cell, is composed of phospholipids and proteins. By defining the cell’s boundary, the plasma membrane controls the intake of substances into the cell and releases substances out of the cell. This selectively permeable membrane is a phospholipid bilayer with proteins inserted in it. It acts as both wall and gateway between the extracellular fluid and the cytoplasm. Both passive mechanisms (diffusion, filtration, and osmosis) and active transports are involved in the transport of a few molecules across the cell membrane. It permits the passage of some substances (wastes and nutrients), while hindering the passage of other substances (phosphates and proteins).
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ANATOMY AND PHYSIOLOGY THE UNITY OF FORM
- Briefly explain why each of the following statements is false, or reword it to make it true.9. The transport maximum (Tm) sets an upper limit on the rate of osmosis.arrow_forwardWhy cytoplasmic membranes are barriers but also permeablearrow_forwardSimple diffusion is defined as the movement ofarrow_forward
- Diffusion requires a membrane to occur. True Falsearrow_forwardSimple diffusion is __________ active passive a form of active transport dependent on ATParrow_forwardBriefly explain why each of the following statements is false, or reword it to make it true.1. If a cell were poisoned so it could not makeATP, osmosis through its membrane wouldceasearrow_forward
- 4 major types of cellsarrow_forwardAll are factors of diffusion that play a role in the rate that it moves. substance concentration polarity size pressure heat solubilityarrow_forwardBriefly explain why each of the following statements is false, or reword it to make it true 7. Tight junctions function primarily to prevent cells from pulling apart.arrow_forward