HW 16

d. a signaling cell

A cell that responds to an environmental condition by the release of a chemical is an example of which of the following elements of cellular communication? a. a signaling molecule b. a G protein-coupled receptor c. none of these d. a signaling cell e. a receptor tyrosine kinase

e. a receptor protein

A protein on a cell surface that binds to a signaling molecule is an example of which of the following elements of cellular communication? a. a signaling cell b. none of these c. a responding cell d. a signaling molecule e. a receptor protein

a. cell-surface receptors bind polar signaling molecules; intracellular receptors bind nonpolar signaling molecules

According to Figure 9.6, what is a key difference between cell signaling by a cell-surface receptor and cell signaling by an intracellular receptor? a. cell-surface receptors bind polar signaling molecules; intracellular receptors bind nonpolar signaling molecules b. signaling molecules that bind to cell-surface receptors lead to cellular responses restricted to the cytoplasm; signaling molecules that bind to intracellular receptors lead to cellular responses restricted to the nucleus c. cell-surface receptors typically bind to signaling molecules that are smaller than those bound by intracellular receptors d. cell-surface receptors bind to specific signaling molecules; intracellular receptors bind any signaling molecule e. none of these

A. b, a, d, c signaling cell, ligand, responding cell, receptor

Choose from the following terms to fill in the blanks in the CORRECT order. a. ligand b. signaling cell c. receptor d. responding cell In communication between cells, the _____ produces the signaling molecule, also known as the _____; the _____ produces the _____, to which the signaling molecule binds,

b. paracrine

Communication between neurons is an example of which type of cell signaling? a. all of these b. paracrine c. contact-dependent d. endocrine e. autocrine

a. both types undergo a conformational change when they bind to their ligand

How are steroid hormone receptors and cell-surface receptors similar? a. both types undergo a conformational change when they bind to their ligand b. when activated, both types carry signals across the plasma membrane c. when bound to their ligand, both types enter the nucleus to activate transcriptioni d. both types cause G proteins to exchange GDP for GTP

a. through a conformational change of the receptor

How does an "activated" receptor transfer information into the cell? a. through a conformational change of the receptor b. by decreased phosphorylation of the receptor c. by altering the ligand-binding site of the receptor d. by increased translation of the receptor

a. it must have receptor proteins

In cell communication, which one of the following is a requirement of the responding cell? a. it must have receptor proteins b. it must be a prokaryotic cell c. it must be a eukaryotic cell d. it must produce signaling molecules

d. a signaling molecule

In the context of cell signaling, to what does the term ligand refer? a. a type of gated channel b. the proteins activated as part of a signal transduction pathway c. the extracellular domain of a receptor protein d. a signaling molecule

C. c, a, b, d, e

Nicotine from cigarette smoke acts as a ligand and associates with specific cells in the nervous system. Nicotine eventually produces feelings of pleasure and well-being. Below are the events that happen in the cellular response to nicotine. Place the events in the correct order to describe the steps in the signaling pathway. a. The acetylcholine receptor is an ion channel, and, when a ligand binds, the ion channel opens. b. An influx of ions carries the signal to the reward areas of the brain. c. Nicotine binds to the transmembrane protein that normally binds the neurotransmitter acetylcholine. d. The signal causes release of dopamine in the brain, which causes good feelings. e. Nicotine is quickly eliminated from the body (causing cravings for more cigarettes to produce good feelings).

d. the cell doesn't have the proper receptor

Of the choices below, what is the MOST likely reason that paracrine signaling does not activate the cell that is producing the signaling molecule? a. the neighboring cells are too far away b. the cell's receptors have a mutation c. the concentration of the signaling molecule is not high enough d. the cell doesn't have the proper receptor

b. the receptor is activated

The first event that happens after a signaling molecule binds to a receptor is: a. the signal is quickly terminated to ensure a moderate response b. the receptor is activated c. there is a cellular response d. the receptor transmits the message in a process called signal transduction

c. all of these

To have communication between cells, you must have a: a. signaling molecule b. receptor c. all of these d. responding cell

d. the ligand-binding site

What determines the specificity of a receptor protein? a. the cytoplasmic domain b. the extracellular domain c. the transmembrane domain d. the ligand-binding site

b. it allows ions to move across the plasma membrane

What does a ligand-gated channel do? a. it binds small, nonpolar signaling molecules b. it allows ions to move across the plasma membrane c. it triggers the activity of a phosphatase d. it activates a G protein

d. either in the nucleus of the cell or in the cytosol

Where would you expect to find the receptor for a nonpolar ligand? a. in the cytosol b. on the cell surface c. in the nucleus of the cell d. either in the nucleus of the cell or in the cytosol

d. autocrine, paracrine, endocrine

Which of the following CORRECTLY lists the types of cellular communication from shortest to longest distance traveled by the signaling molecule to reach its responding cell? a. paracrine, autocrine, endocrine b. endocrine, paracrine, autocrine c. autocrine, endocrine, paracrine d. autocrine, paracrine, endocrine

b. all of these

Which of the following types of cellular activities can be a response to cell signaling? a. gene expression patterns are changed b. all of these c. cell division is triggered d. cell signals are released to communicate with other cells e. enzyme activities are changed

b. a receptor that binds a nonpolar steroid hormone and activates transcription

Which of the following would NOT be considered a cell-surface receptor? a. a receptor that causes GDP to be exchanged for GTP in a G protein b. a receptor that binds a nonpolar steroid hormone and activates transcription c. a receptor that allows ions to enter the cell when a ligand binds d. a receptor that must form a dimer after binding the ligand to transmit a signal

d. ligand-gated ion channel

Which type of receptor is involved in rapid responses of muscle cells and neurons? a. receptor kinase b. G protein-coupled receptor c. intracellular receptor d. ligand-gated ion channel