Exam 11: Cellcell Interactions

Acetylcholine is a neurotransmitter that binds to receptors on skeletal muscle cells. The receptor-signal complex brings about a series of events that result in contraction of skeletal muscle. Venom from black widow spiders causes an explosive release of acetylcholine. What would that do to its victims?

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its ________.

In general, a signal transmitted via phosphorylation of a series of proteins ________.

H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted the cell-cell interaction (cell junctions), and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson's experiments?

Integrins are integral membrane proteins. They are often attached to ________.

Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must ________.

For the following question(s), match the labeled component of the cell membrane in the figure with its description. -Which component is a protein fiber of the extracellular matrix?

When yeast cells of the "a" mating type are exposed to a solution of "α" pheromones ________.

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?

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through ________.

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

The activation of receptor tyrosine kinases is characterized by ________.

One characteristic of life and living systems is that they are able to adapt. In general, cells interact with other cells and their environment through the action of their ________.

Put the steps of the process of signal transduction in the order they occur: 1) A conformational change in the signal-receptor complex activates an enzyme. 2) Protein kinases are activated. 3) A signal molecule binds to a receptor. 4) Target proteins are phosphorylated. 5) Second messenger molecules are released.

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

A G-protein receptor with GTP bound to it ________.

The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via which of the following?

Signals from the extracellular matrix to the cytoskeleton may be transmitted by ________.

Forms of the Ras protein found in tumors usually cause which of the following?

Which of the following statements about quorum sensing is FALSE? Quorum sensing ________.