Ücretsiz Kullanmaya Başla

Cell signaling Transitional Reasoning Practice

Biology · Cell Communication & the Cell Cycle · Biology · Cell Communication

1 Biology practice questions on Cell signaling. Questions that build towards applied reasoning.

Layout:

Choose how questions appear in the preview and test.

Preview the questions below, then start to answer and see your results.

Questions

  1. 1.

    In an experiment investigating cell communication, researchers treated cultured liver cells with a peptide hormone that stimulates glycogen breakdown via a G protein-coupled receptor (GPCR) signaling cascade. In a mutant cell line that completely lacks functional cell-surface GPCRs, the addition of the extracellular hormone fails to trigger glycogen breakdown; however, directly microinjecting cyclic AMP (cAMP) into these mutant cells restores full glycogen breakdown. Based on these findings, which conclusion is best supported regarding the role and position of cAMP in this pathway?

    • A) Cyclic AMP operates downstream of the cell-surface receptor as an intracellular second messenger to mediate the cellular response.
    • B) Cyclic AMP functions upstream of the membrane receptor to enhance hormone binding on the extracellular surface.
    • C) The extracellular hormone directly catalyzes glycogen degradation once inside the cell without requiring intermediate messengers.
    • D) The cell-surface receptor directly cleaves glycogen independently of any cytosolic second messengers.

Answers and step-by-step solutions appear after you finish the test.