Download Problem 5: Bacterial Cell Signaling

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Problem 1: Receptors
A protein receptor binds a hormone outside the cell membrane and activates a protein
kinase inside the cell. Is the receptor a peripheral or integral membrane protein?
Problem 2: Signal Responses I
Signaling between cells usually results in the activation of protein _______.
Problem 3: Signal Responses II
Tutorial to help answer the question
Which of the following is NOT a typical event associated with cell signaling?
Problem 4: Kinds of Signals
A cell secretes growth factors that have a slow diffusion rate, and interacting only
with other cells in the immediate area is an example of _______________ signaling.
Problem 5: Bacterial Cell Signaling
E.coli respond to increased solute concentrations by phosphorylation of the membrane
receptor _______________, which transfers a phosphate to the subcellular second
messenger ______________ that initiates transcription of the ___________ gene
producing a protein that can prevent solute entry and preserve the osmotic integrity of
the cell.
Problem 6: Steroid Hormones
Estrogen and testosterone are steroid hormones, and are most likely to bind to:
Problem 7: Second Messengers
Sending a signal through the cell membrane can lead to the production of second
messengers inside the cell. Which of the following can serve as second messengers?
Problem 8: Protein Kinase Cascades
Some receptors for growth factors activate a protein kinase cascade, with the
participation of multiple enzymes to effect a change in gene expression. Which of the
following statements about a protein kinase cascade are true?
Problem 9: G-proteins
The endogenous GTPase activity of G-proteins serves to:
Problem 10: Signaling Events
In a fight-or-flight response, epinephrine released by the adrenal glands binds to a
membrane receptor on muscle cells. Which of the following events result from ligand
binding?
Problem 11: Gap Junctions
Direct cellular connections such as gap junctions in animal cells and plasmodesmata
in plant cells permit:
Problem 12: Cancer Therapy
A new drug, STI-571 or Gleevec specifically inhibits the Abl tyrosine kinase that is
mutated in chronic myeloid leukemia. Treating patients with the drug dramatically
improves survival, but people with a "blast crisis" form of the cancer begin to develop
resistance. Which of the following statements are important conclusions from studies
on the use of STI-571 in cancer treatment?