Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of
A) phosphorylated proteins.
B) GTP.
C) cAMP.
D) adenylyl cyclase.
E) activated G proteins.
Answer: C
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AP Biology Chapter 11
- What role does a transcription factor play in a signal transduction pathway?
- A toxin that inhibits the production of GTP would interfere with the function of a signal transduction pathway that is initiated by the binding of a signal molecule to _____ receptors.
- Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
- Protein phosphorylation is commonly involved with all of the following except
- Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells?
- The activation of receptor tyrosine kinases is characterized by
- Binding of a signaling molecule to which type of receptor leads directly to a change in distribution of ions on opposite sides of the membrane?
- Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because
- If an adult person has a faulty version of the human-analog to ced-4 ofthe nematode, which of the following might more likely result?
- Human caspases can be activated by
- The main proteases involved in apoptosis are
- Why has C. elegans proven to be a useful model for understanding apoptosis?
- The termination phase of cell signaling requires which of the following?
- What are scaffolding proteins?
- The use of beta 2 antagonist drugs may be useful in asthma because
- As humans, we have receptors for two kinds of beta adrenergic compounds such as catecholamines. Cardiac muscle cells have beta 1 receptors that promote increased heart rate. Some drugs that slow heart rate are called beta blockers. Smooth muscle cells, however, have beta 2 receptors which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma. The description above illustrates which of the following?
- Which of the substances below is a protein that can hold several other relay proteins as it binds to an activated membrane receptor?
- A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?
- One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. cGMP is inhibited, therefore the signal is prolonged. The original signal that is now inhibited would have
- Which of the following is a correct association?
- Which of the following statements is true?
- An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum?
- If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to
- Adenylyl cyclase has the opposite effect of which of the following?