Exam 7: Cell Communication and Multicellularity

Refer to the graph below. The graph shows data for the amount of connexin protein present in cells of the right ventricle and cells of the left ventricle isolated from patients who experienced heart failure due to arrhythmia.The quantities are expressed as percentage of the amount of connexin protein present in controls, determined using heart cells from individuals without heart failure.Which hypothesis is supported by these data?

Refer to the table below. The table lists three different biological responses that result from cAMP-mediated signal transduction pathways.The "yes" and "no" references indicate which cells are capable of displaying the three biological responses.This information provides evidence in support of which statement about signal transduction pathways?

Refer to the figure below, which shows the signal transduction pathway initiated by the binding of an odorant molecule to an olfactory receptor of an olfactory neuron. Information will be sent to the brain because of changes in ion concentrations within the neuron.What specific event is most directly responsible for the change in intracellular ion concentrations?

Refer to the table below. The table shows data collected from studies comparing normal and mutant cells.Mutant cells differ from normal cells in having a mutation in the gene encoding a receptor protein.The mutation results in a single amino acid change from a glutamic acid to a lysine.Which is a possible effect of the mutation?

The basic elements necessary for a signal transduction pathway within a cell are

Refer to the figure below showing a transmembrane protein that functions in a signal transduction pathway. In which order are the parts of the protein affected during a single event of signal transduction?

When activated, some receptor proteins catalyze the transfer of a phosphate group from ATP to another protein.Such receptor proteins are known as protein _______.

Chemical signals called paracrine signals are transported from the secreting cell to a target cell by

Refer to the figure below. Which equation represents the equilibrium condition? In all equations shown, "R" represents a receptor with no ligand bound, "L" represents a free ligand in solution, and "RL" represents a receptor bound to a ligand.

Which is the correct order of the steps in a generalized signal transduction pathway?

Refer to the figure below. Which property of Volvox internal reproductive cells and external nonreproductive cells can be used as evidence to support current theory about how multicellularity evolved?

A benefit of the many steps involved in a protein kinase cascade is that they involve

In the mammalian eye, the lens is composed of a large number of cells called lens cells.Only lens cells along the edges are close to a blood supply where they exchange nutrients and waste molecules.Lens cells in the middle of the lens are connected via gap junctions.Cataracts appear as a cloudiness that develops in the lenses of the eye, often with age.Biologists have suspected that cataracts result from a disruption in intercellular communication between lens cells through gap junctions.Which type of investigation would best provide more information about whether gap junctions are involved in cataract formation?

Refer to the table below. The components listed in the table are molecules that participate in a signal transduction pathway.A researcher measured the number of molecules of each component that were activated during one signal transduction event and summarized them as shown.From this information, a sketch could be made to show the sequential order of the components in the pathway.From first to last, they would be _______.

Refer to the table below, which lists three biological responses that result from cAMP-mediated signal transduction pathways.The "yes" and "no" references in the table indicate which cells are capable of displaying the three biological responses. Which statement explains how the same second-messenger molecule, cAMP, can be involved in all of these different pathways?

Receptors bind to their ligands noncovalently, according to chemistry's law of mass action.This means that

Protein kinase receptors phosphorylate themselves and/or other proteins when activated, resulting in a(n)

The second messenger cAMP can be effective in many different signal transduction pathways because it is a small molecule, which enables its target proteins to have specific sites that bind the cAMP molecule.When this happens, the target proteins undergo a change in _______ with a concomitant change in their biological activity.

Refer to the table below, which shows results from investigations of four mouse lineages. Three of these lineages have different mutations that disrupt the signal transduction pathway that allows mice to recognize sweet taste in response to sugar.For each mouse group, each component of the signal transduction pathway was tested in terms of its response to sugar, which was provided as a stimulus of the pathway.In the table, "+++" refers to high levels of activity in the response to sugar, and "0" refers to no activity in the response to sugar.These results provide evidence for which role of calcium ion channels in this signal transduction pathway?

Refer to the figure below. How is it a benefit to the cell to have so many protein kinase molecules participating in the signal transduction pathway shown?