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Overview of Signaling Molecules quiz #1 Flashcards

Overview of Signaling Molecules quiz #1
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  • What are the main classes of extracellular signaling molecules, and how do they differ in their ability to cross the plasma membrane?

    The main classes are steroid hormones, gases, neurotransmitters, peptide hormones, growth factors, and eicosinoids. Steroid hormones and gases can diffuse through the plasma membrane, while peptide hormones, growth factors, and eicosinoids cannot and must bind to membrane receptors.
  • How do steroid hormones typically exert their effects within a target cell?

    Steroid hormones diffuse through the plasma membrane and bind to nuclear receptors, which then initiate gene transcription to produce specific cellular responses.
  • Describe the three main types of signaling based on the distance the signal travels: endocrine, paracrine, and autocrine.

    Endocrine signaling involves long-distance signals (like hormones) traveling through the circulatory system; paracrine signaling acts over short distances between nearby cells (e.g., neurotransmitters, growth factors); autocrine signaling occurs when a cell signals to itself, often seen with eicosinoids.
  • What are two main ways that a cell receptor can transmit a signal after binding a signaling molecule?

    A receptor can either pass the signal to a second messenger protein, which then activates further signaling inside the cell, or act as a hub to recruit and activate multiple proteins directly at the receptor site.
  • Why can the same signaling molecule, such as acetylcholine, produce different responses in different cell types?

    Different cell types have distinct sets of proteins and signaling pathways, so the same signaling molecule can trigger varied responses depending on the cell's specific receptors and internal machinery.
  • What are the main classes of extracellular signaling molecules, and how do they differ in their ability to cross the plasma membrane?

    The main classes are steroid hormones, gases, neurotransmitters, peptide hormones, growth factors, and eicosinoids. Steroid hormones and gases can diffuse through the plasma membrane, while peptide hormones, growth factors, and eicosinoids cannot and must bind to membrane receptors.
  • How do steroid hormones typically exert their effects within a target cell?

    Steroid hormones diffuse through the plasma membrane and bind to nuclear receptors, which then initiate gene transcription to produce specific cellular responses.
  • Describe the three main types of signaling based on the distance the signal travels: endocrine, paracrine, and autocrine.

    Endocrine signaling involves long-distance signals (like hormones) traveling through the circulatory system; paracrine signaling acts over short distances between nearby cells (e.g., neurotransmitters, growth factors); autocrine signaling occurs when a cell signals to itself, often seen with eicosinoids.
  • What are two main ways that a cell receptor can transmit a signal after binding a signaling molecule?

    A receptor can either pass the signal to a second messenger protein, which then activates further signaling inside the cell, or act as a hub to recruit and activate multiple proteins directly at the receptor site.
  • Why can the same signaling molecule, such as acetylcholine, produce different responses in different cell types?

    Different cell types have distinct sets of proteins and signaling pathways, so the same signaling molecule can trigger varied responses depending on the cell's specific receptors and internal machinery.