Exam 11: Cell Communication

Particular receptor tyrosine kinases (RTKs)that promote excessive cell division are found at high levels in various cancer cells. HER2 is an RTK that is present at excessively high levels in some breast cancer cells. Herceptin is a protein that binds to HER2 and inhibits cell division. Herceptin may be an effective treatment for breast cancer treatment under which of the following conditions?

Viagra causes dilation of blood vessels and increased blood flow to the penis, facilitating erection. Viagra acts by inhibiting which of the following events?

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following?

Which of the following statements describes a likely effect of a drug designed that inhibits the cellular response to testosterone?

Scientists have found that extracellular matrix components may induce specific gene expression in embryonic tissues such as the liver and testes. For this to happen, there must be direct communication between the extracellular matrix and the developing cells. Which kind of transmembrane protein would most likely be involved in this kind of induction?

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogen and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?

In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

Which of the following statements about a G protein signaling pathway is true?

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following, if found in cells or organisms as they age, would provide evidence that this is related to cell signaling?

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they ________.

When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?

The receptors for steroid hormones are located inside the cell instead of the membrane surface like most other signal receptors. How do steroids gain access to their receptors?

Cells that are infected, damaged, or have reached the end of their functional life span often undergo "programmed cell death." This controlled cell suicide is called apoptosis. Select the appropriate description of this event on a cell's life cycle.

Which of the following statements is true of signal molecules?

Which of the following is the most plausible explanation for why an animal cell would be unable to reduce the Ca²⁺ concentration in its cytosol compared with the extracellular fluid?

An inhibitor of which of the following enzymes could be used to block the release of calcium from the endoplasmic reticulum?

Not all intercellular signals require transduction. Which one of the following signals would be processed without transduction?

Which of the following processes generally requires protein phosphorylation?

Consider this pathway: Epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP The second messenger in this pathway is ________.

Use the following figure to answer the question. Which of the following types of signaling is represented in the figure?