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Biology LibreTexts

9.1A: Signaling Molecules and Cellular Receptors

  • Page ID
    13214
  • Cellular communication ensures regulation of biological processes within various environments from single-celled to multicellular organisms.

    Learning Objectives

    • Explain the importance of cell communication

    Key Points

    • The ability of cells to communicate through chemical signals originated in single cells and was essential for the evolution of multicellular organisms.
    • In multicellular organisms, cells send and receive chemical messages constantly to coordinate the actions of distant organs, tissues, and cells.
    • Cells can receive a message, transfer the information across the plasma membrane, and then produce changes within the cell in response to the message.
    • Single-celled organisms, like yeast and bacteria, communicate with each other to aid in mating and coordination.
    • Cellular communication has developed as a means to communicate with the environment, produce biological changes, and, if necessary, ensure survival.

    Key Terms

    • biofilm: a thin film of mucus created by and containing a colony of bacteria and other microorganisms

    Introduction: Signaling Molecules and Cellular Receptors

    Imagine what life would be like if you and the people around you could not communicate. You would not be able to express your wishes to others, nor could you ask questions to find out more about your environment. Social organization is dependent on communication between the individuals that comprise that society; without communication, society would fall apart.

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    Communication is Key: Have you ever become separated from a friend while in a crowd? If so, you know the challenge of searching for someone when surrounded by thousands of other people. If you and your friend have cell phones, your chances of finding each other are good. A cell phone’s ability to send and receive messages makes it an ideal communication device.

    As with people, it is vital for individual cells to be able to interact with their environment. This is true whether a cell is growing by itself in a pond or is one of many cells that form a larger organism. In order to properly respond to external stimuli, cells have developed complex mechanisms of communication that can receive a message, transfer the information across the plasma membrane, and then produce changes within the cell in response to the message.

    In multicellular organisms, cells send and receive chemical messages constantly to coordinate the actions of distant organs, tissues, and cells. The ability to send messages quickly and efficiently enables cells to coordinate and fine-tune their functions.

    While the necessity for cellular communication in larger organisms seems obvious, even single-celled organisms communicate with each other. Yeast cells signal each other to aid mating. Some forms of bacteria coordinate their actions in order to form large complexes called biofilms or to organize the production of toxins to remove competing organisms. The ability of cells to communicate through chemical signals originated in single cells and was essential for the evolution of multicellular organisms. The efficient and error-free function of communication systems is vital for all forms of life.