Chapter 11

Last update by mayur on 04/07/2014
823242 People have viewed this Quiz
  • Share

Phosphorylation cascades involving a series of protein kinases are useful for cellular signaltransduction because

A) they are species specific.

B) they always lead to the same cellular response.

C) they amplify the original signal manyfold.

D) they counter the harmful effects of phosphatases.

E) the number of molecules used is small and fixed.

Answer:

C) they amplify the original signal manyfold.



View Chapter 11 as Flashcard Deck

Related Quiz Content
  • feldman2009
    Answered in Chapter 11

    Binding of a signaling molecule to which type of receptor leads directly to a change indistribution of ions on opposite sides of the membrane?

    A) receptor tyrosine kinase

    B) G protein-coupled receptor

    C) phosphorylated receptor tyrosine kinase dimer

    D) ligand-gated ion channel

    E) intracellular receptor



    D) ligand-gated ion channel



  • feldman2009
    Answered in Chapter 11

    The activation of receptor tyrosine kinases is characterized by

    A) dimerization and phosphorylation.

    B) IP3binding.

    C) a phosphorylation cascade.

    D) GTP hydrolysis.

    E) channel protein shape change.

    A) dimerization and phosphorylation.



  • feldman2009
    Answered in Chapter 11

    Which observation suggested to Sutherland the involvement of a second messenger inepinephrine's effect on liver cells?

    A) Enzymatic activity was proportional to the amount of calcium added to a cell-free extract.

    B) Receptor studies indicated that epinephrine was a ligand.

    C) Glycogen breakdown was observed only when epinephrine was administered to intact cells.

    D) Glycogen breakdown was observed when epinephrine and glycogen phosphorylase werecombined.

    E) Epinephrine was known to have different effects on different types of cells.



    C) Glycogen breakdown was observed only when epinephrine was administered to intact cells.



  • feldman2009
    Answered in Chapter 11

    Protein phosphorylation is commonly involved with all of the following except

    A) regulation of transcription by extracellular signal molecules.

    B) enzyme activation.

    C) activation of G protein-coupled receptors.

    D) activation of receptor tyrosine kinases.

    E) activation of protein kinase molecules.



    C) activation of G protein-coupled receptors.



  • feldman2009
    Answered in Chapter 11

    Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells butaffect only target cells because

    A)only target cells retain the appropriate DNA segments.

    B) intracellular receptors are present only in target cells.

    C) most cells lack the Y chromosome required.

    D) only target cells possess the cytosolic enzymes that transduce the testosterone.

    E) only in target cells is testosterone able to initiate the phosphorylation cascade leading toactivated transcription factor.



    B) intracellular receptors are present only in target cells.