Mastering Biology (Test questions with 100% correct answers)

Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? correct answers estrogen A(n) _____ is an example of a signal molecule that can bind to an intracellular receptor and thereby cause a gene to be turned on or off. correct answers Steroid Thyroid hormones bind to _____ receptors. correct answers intracellular Which of these is a logical signal transduction pathway? correct answers A G-protein-linked receptor activates G protein, which activates phospholipase C, which cleaves a membrane lipid to form IP3, which binds to a calcium channel on the ER, which opens to release calcium ions into the cytoplasm, which bind to an intracellular enzyme that carries out a response. What role does a transcription factor play in a signal transduction pathway? correct answers By binding to DNA it triggers the transcription of a specific gene. Which of the following, when activated by a signal transduction pathway, moves from the cytoplasm to the nucleus of a cell? correct answers Transcription factor A signal transduction pathway is initiated when a _____ binds to a receptor. correct answers signam molecule Which of these acts as a second messenger? correct answers Cyclic AMP Calcium ions that act as second messengers are stored in _____. correct answers endoplasmic reticula _____ catalyzes the production of _____, which then opens an ion channel that releases _____ into the cell's cytoplasm. correct answers Phospholipase C ... IP3 .... Ca2+ A protein kinase activating many other protein kinases is an example of _____. correct answers Amplification Which type of hormone is lipid soluble? correct answers Steroids Which molecules determine the tissue specificity of hormones? correct answers Receptors True or false? Lipid-insoluble hormones affect their target cells by binding to receptors inside the cell. correct answers False