Intracellular Receptors and Cellular Signaling
88 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which type of signaling molecules can diffuse across the plasma membrane to bind to intracellular receptors?

  • Protein hormones
  • Hydrophilic signaling molecules
  • Peptide hormones
  • Steroid hormones (correct)

    • What is the common mechanism of action for thyroid hormone, vitamin D3, and retinoic acid?

  • Binding to intracellular receptors (correct)
  • Activation of ion channels
  • Binding to cell surface receptors
  • Inhibition of enzyme activity

    • Which group of signaling molecules are synthesized from cholesterol?

  • Steroid hormones (correct)
  • Hydrophilic signaling molecules
  • Protein hormones
  • Peptide hormones

    • Which hormones are produced by the gonads?

    <p>Estrogen and progesterone</p> Signup and view all the answers

    Which hormones are produced by the adrenal gland?

    <p>Corticosteroids</p> Signup and view all the answers

    What is the role of corticosteroids?

    <p>Stimulate glucose production</p> Signup and view all the answers

    How are steroid hormones able to enter cells?

    <p>By diffusion across the plasma membrane</p> Signup and view all the answers

    Which hormone plays important roles in development and regulation of metabolism?

    <p>Thyroid hormone</p> Signup and view all the answers

    What is the role of vitamin D3?

    <p>Regulate Ca2+ metabolism</p> Signup and view all the answers

    What is the role of retinoic acid and related compounds?

    <p>Play important roles in vertebrate development</p> Signup and view all the answers

    Which family of proteins do the intracellular receptors for steroids, thyroid hormone, vitamin D3, and retinoic acid belong to?

    <p>Nuclear receptor superfamily</p> Signup and view all the answers

    What are the distinct effects of ligand binding on different receptors within the nuclear receptor superfamily?

    <p>Some receptors are inactive in the absence of hormone</p> Signup and view all the answers

    Which molecule is bound to the glucocorticoid receptor in the absence of hormone?

    <p>Hsp90 chaperones</p> Signup and view all the answers

    What happens when glucocorticoid binds to its receptor?

    <p>Hsp90 is displaced and receptor dimers are formed</p> Signup and view all the answers

    In the absence of hormone, what is the role of the thyroid hormone receptor?

    <p>It represses transcription of its target genes</p> Signup and view all the answers

    What happens when hormone binds to the thyroid hormone receptor?

    <p>It interacts with coactivators instead of corepressors</p> Signup and view all the answers

    What is the role of ligand binding on the function of nuclear receptors?

    <p>Regulates their function as activators or repressors of target genes</p> Signup and view all the answers

    Which domain is NOT present in the intracellular receptors for steroids, thyroid hormone, vitamin D3, and retinoic acid?

    <p>Enzyme activity domain</p> Signup and view all the answers

    What is the role of the nuclear receptor superfamily in gene expression regulation?

    <p>They activate or repress transcription of target genes</p> Signup and view all the answers

    What is the role of ligand binding on the activity of the receptor as a transcriptional regulatory molecule?

    <p>It alters the activity of the receptor</p> Signup and view all the answers

    Which molecules bind to intracellular receptors expressed by hormonally responsive target cells?

    <p>Steroids, thyroid hormone, vitamin D3, and retinoic acid</p> Signup and view all the answers

    Which family of proteins do the intracellular receptors belong to?

    <p>Nuclear receptor superfamily</p> Signup and view all the answers

    What are the three related domains found in the intracellular receptors?

    <p>Ligand binding, DNA binding, and transcriptional activation</p> Signup and view all the answers

    How do steroid hormones and related molecules directly regulate gene expression?

    <p>By binding to intracellular receptors</p> Signup and view all the answers

    What is the role of glucocorticoid binding in the glucocorticoid receptor?

    <p>It induces a conformational change in the receptor</p> Signup and view all the answers

    What happens to the glucocorticoid receptor in the absence of hormone?

    <p>It is bound to Hsp90 chaperones</p> Signup and view all the answers

    What is the role of the thyroid hormone binding in the thyroid hormone receptor?

    <p>It induces a conformational change in the receptor</p> Signup and view all the answers

    What happens to the thyroid hormone receptor in the absence of hormone?

    <p>It is associated with a corepressor complex</p> Signup and view all the answers

    How does hormone binding affect the activity of the receptor in other cases?

    <p>It alters the activity of the receptor as a transcriptional regulatory molecule</p> Signup and view all the answers

    What is the outcome of hormone binding in other cases?

    <p>The receptor interacts with coactivators instead of corepressors</p> Signup and view all the answers

    True or false: All signaling molecules act by binding to receptors expressed on the target cell surface.

    <p>False</p> Signup and view all the answers

    True or false: Thyroid hormone is synthesized from cholesterol.

    <p>False</p> Signup and view all the answers

    True or false: Retinoic acid and related compounds play important roles in vertebrate development.

    <p>True</p> Signup and view all the answers

    True or false: Steroids, thyroid hormone, vitamin D3, and retinoic acid bind to extracellular receptors expressed by hormonally responsive target cells.

    <p>False</p> Signup and view all the answers

    True or false: Ligand binding of the nuclear receptor superfamily proteins regulates the function of ligand binding, DNA binding, and transcriptional activation.

    <p>True</p> Signup and view all the answers

    True or false: Hormone binding alters the activity of the receptor as a transcriptional regulatory molecule in all cases.

    <p>False</p> Signup and view all the answers

    Which of the following is NOT a characteristic of neurotransmitters?

    <p>They can cross the target cell plasma membrane</p> Signup and view all the answers

    Which signaling molecule is responsible for signaling the dilation of blood vessels that leads to penile erection?

    <p>Nitric oxide</p> Signup and view all the answers

    What is the role of G proteins in neurotransmitter signaling?

    <p>They regulate ion channels</p> Signup and view all the answers

    What is the molecular basis of nitric oxide (NO) action?

    <p>Activating guanylyl cyclase to stimulate synthesis of cyclic GMP</p> Signup and view all the answers

    Which plant hormone was the first to be identified?

    <p>Auxin</p> Signup and view all the answers

    What is the role of nitroglycerin in the treatment of heart disease?

    <p>It is converted to nitric oxide (NO) to dilate blood vessels and increase blood flow to the heart</p> Signup and view all the answers

    What is one of the effects of auxins in plants?

    <p>Stem elongation</p> Signup and view all the answers

    True or false: Nitric oxide (NO) is a major paracrine signaling molecule in the circulatory system.

    <p>True</p> Signup and view all the answers

    True or false: Nitric oxide (NO) binds to a receptor that regulates transcription.

    <p>False</p> Signup and view all the answers

    True or false: Nitric oxide (NO) stimulates synthesis of cyclic GMP inside the cell by activating guanylyl cyclase.

    <p>True</p> Signup and view all the answers

    True or false: Neurotransmitters are able to cross the target cell plasma membrane.

    <p>False</p> Signup and view all the answers

    True or false: Plant hormones regulate plant growth and development.

    <p>True</p> Signup and view all the answers

    True or false: Auxins induce plant cell elongation by strengthening the cell wall.

    <p>False</p> Signup and view all the answers

    True or false: The first plant hormone to be identified was auxin.

    <p>True</p> Signup and view all the answers

    Which of the following is NOT true about G proteins?

    <p>G proteins are activated by hydrolysis of GTP</p> Signup and view all the answers

    How many different α subunits are encoded by the human genome?

    <p>21</p> Signup and view all the answers

    What is the role of RGS proteins in G protein signaling?

    <p>RGS proteins stimulate hydrolysis of GTP</p> Signup and view all the answers

    Which of the following is NOT a type of signaling molecule in animals?

    <p>Steroids</p> Signup and view all the answers

    Which of the following is NOT an example of a peptide hormone?

    <p>Epidermal growth factor</p> Signup and view all the answers

    Who discovered nerve growth factor (NGF) and serendipitously discovered epidermal growth factor (EGF)?

    <p>Both Rita Levi-Montalcini and Stanley Cohen</p> Signup and view all the answers

    Which group of polypeptide growth factors is responsible for regulating the development and differentiation of blood cells and controlling the activities of lymphocytes during the immune response?

    <p>Cytokines</p> Signup and view all the answers

    Which type of signaling molecules act by binding to cell surface receptors and are unable to cross the plasma membrane of their target cells?

    <p>Peptide hormones</p> Signup and view all the answers

    What is the basis for a variety of diseases, including many kinds of cancer?

    <p>Abnormal expression of the EGF receptor</p> Signup and view all the answers

    Which family of cell surface receptors transmits signals to intracellular targets via the intermediary action of guanine nucleotide-binding proteins called G proteins?

    <p>G protein-coupled receptors</p> Signup and view all the answers

    True or false: Peptide hormones include insulin and the hormones produced by the pituitary gland?

    <p>True</p> Signup and view all the answers

    True or false: Neuropeptides are naturally occurring compounds that bind to the same receptors on brain cells as morphine does?

    <p>True</p> Signup and view all the answers

    True or false: Epidermal growth factor (EGF) stimulates cell proliferation?

    <p>True</p> Signup and view all the answers

    True or false: The activity of the α subunit is terminated by hydrolysis of the bound GDP, which is stimulated by RGS proteins?

    <p>False</p> Signup and view all the answers

    True or false: The human genome encodes 21 different β subunits of the G protein?

    <p>False</p> Signup and view all the answers

    True or false: Different G proteins always associate with the same receptors?

    <p>False</p> Signup and view all the answers

    True or false: PDGF stimulates the proliferation and movement of fibroblasts in the vicinity of the clot, contributing to regrowth of damaged tissue.

    <p>True</p> Signup and view all the answers

    True or false: Polypeptide growth factors that remain associated with the plasma membrane function as signaling molecules during direct cell-cell interactions.

    <p>True</p> Signup and view all the answers

    True or false: G protein-coupled receptors are characterized by seven membrane-spanning α helices.

    <p>True</p> Signup and view all the answers

    True or false: G proteins consist of three subunits designated α, β, and γ.

    <p>True</p> Signup and view all the answers

    Which enzyme is responsible for the formation of cAMP from ATP?

    <p>Adenylyl cyclase</p> Signup and view all the answers

    What is the role of cAMP-dependent protein kinase in animal cells?

    <p>It phosphorylates serine residues on target proteins</p> Signup and view all the answers

    Which protein kinase is phosphorylated and activated by protein kinase A in the regulation of glycogen breakdown?

    <p>Phosphorylase kinase</p> Signup and view all the answers

    Which enzyme catalyzes the synthesis of many molecules of cAMP?

    <p>Adenylyl cyclase</p> Signup and view all the answers

    What is the regulatory sequence called that is found in specific target genes activated by cAMP?

    <p>cAMP response element</p> Signup and view all the answers

    Which enzyme dephosphorylates the serine residues of proteins phosphorylated by protein kinase A?

    <p>Protein phosphatase 1</p> Signup and view all the answers

    In the sensory neurons of the nose, how does cAMP directly regulate ion channels?

    <p>By directly opening Na+ channels</p> Signup and view all the answers

    Which family of proteins is responsible for phosphorylating the STAT proteins?

    <p>JAK family kinases</p> Signup and view all the answers

    What is the role of the STAT proteins in gene expression?

    <p>They stimulate transcription of target genes</p> Signup and view all the answers

    Which group of proteins are responsible for signaling downstream of cytokine receptors and receptor tyrosine kinases?

    <p>Src family kinases</p> Signup and view all the answers

    Which molecules are responsible for the attachment of cells to the extracellular matrix?

    <p>Integrins</p> Signup and view all the answers

    Which family of cell surface receptors are directly linked to intracellular enzymes?

    <p>Tyrosine kinases</p> Signup and view all the answers

    What was the first tyrosine kinase discovered during studies of?

    <p>Rous sarcoma virus</p> Signup and view all the answers

    What is the common structural organization of receptor tyrosine kinases?

    <p>Extracellular ligand-binding domain, single transmembrane α helix, and cytosolic C-terminal domain with tyrosine kinase activity</p> Signup and view all the answers

    Which of the following is NOT a characteristic of receptor tyrosine kinases?

    <p>They are associated with nonreceptor tyrosine kinases</p> Signup and view all the answers

    What is the role of SH2 domains in receptor tyrosine kinase signaling?

    <p>They bind to phosphotyrosine-containing peptides</p> Signup and view all the answers

    How do cytokine receptors differ from receptor tyrosine kinases?

    <p>Cytokine receptors lack ligand-binding domains</p> Signup and view all the answers

    What are the key targets of the JAK kinases associated with cytokine receptors?

    <p>STAT proteins</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser