• 1.0. MODULE 1: TERMINOLOGY/HOMEOSTASIS
  • 2.0. MODULE 2: INORGANIC CHEMISTRY
  • 3.0. MODULE 3: ORGANIC CHEMISTRY
  • 4.0. MODULE 4: THE CELL
  • 5.0. MODULE 5: CELL MEMBRANES-STRUCTURE AND TRANSPORT
  • 6.0. MODULE 6: NERVOUS SYSTEM ORGANIZATION
  • 7.0. MODULE 7: SKELETAL MUSCLE
  • 8.0. MODULE 8: METABOLISM
  • 9.0. MODULE 9: CONTROL OF BODY MOVEMENT
  • 10.0. MODULE 10: THE AUTONOMIC NERVOUS SYSTEM
  • 11.0. MODULE 11: THE BRAIN
  • 12.0. MODULE 12: SPECIAL SENSES
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  • Translations
  • 5.2

    MEMBRANE TRANSPORT

    One of the primary functions of the membrane is to separate the intracellular environment from its extracellular environment. This separation is crucial for the maintenance of the proper conditions for cell function. To perform this important function, the membrane must regulate what enters and leaves the cell. For example, the proper nutrients must be allowed to enter, and wastes must be allowed to leave the cell. Additionally, some things must not be permitted entrance to or exit from the cell. In this section, we will discuss how various substances are moved across the plasma membrane.

    Passive vs Active Processes

    Watch this Video on Passive Diffusion´╗┐

    Watch this Video on Active Diffusion

    Processes that move substances across membranes can be grouped into two general categories based on whether the process requires energy or not. If no energy input is required for the transport, we say particles move via passive transport. On the other hand, if the process requires cellular energy, then it is an active transport process.

    Simple DiffusionFacilitated DiffusionActive TransportOsmosis

    This content is provided to you freely by BYU-I Books.

    Access it online or download it at https://books.byui.edu/bio_264_anatomy_phy_I/52___membrane_transp.