Chapter 9 Vocab: Cell Communication

Question 1

Define Cell signaling

Answer 1

The system of communication between cells through signaling pathways

Question 2

Define Synapse

Answer 2

A site where a neuron makes a communicating connection with another neuron or an effector such as a muscle fiber or gland

Question 3

Define Synaptic signaling (not found in the glossary)

Answer 3

• In the brain, a ligand-gate ion channel may remain active for less than 10 milliseconds.
• Occurs at chemical synapses between two neurons or between a neuron and a muscle cell

Question 4

Define Electrical synapse

Answer 4

In the nervous system where plasma membranes of two connecting neurons are in direct contact and communication across such a synapse occurs by the direct flow of an electrical signal

Question 5

Define Cell-Cell recognition

Answer 5

Communication by direct contact. Adjacent cells can communicate with each other when a membrane protein in one cell binds selectively to a membrane in the other cell.

Question 6

Define Extracellular fluid

Answer 6

The fluid occupying the spaces between cells in multicellular animals

Question 7

Define Chemical synapses

Answer 7

In the nervous system where the plasma membranes of the presynaptic and postsynaptic cells are separated by a narrow gap. Communication across such a synapse occurs by means of a neurotransmitter; that is an electrical impulse arriving at an axon terminal of the presynaptic cell triggers release of a neurotransmitter that crosses the gap and binds to a receptor on the postsynaptic cell, triggering an electrical impulse in that cell

Question 8

Define Hormone

Answer 8

A signaling molecule secreted by a cell that can alter the activities of any cell with receptors for it; in animals, typically a molecule produced by one tissue and transported via the bloodstream to another specific tissue to alter its physiological activity

Question 9

Define Reception

Answer 9

In signal transduction, the binding of a signal molecule with a specific receptor in a target cell. In neural signaling, the first of four components in which a stimulus is detected by specialized sensory neurons

Question 10

Define Ligand

Answer 10

A molecule that binds to another molecule

Question 11

Define Transduction

Answer 11

In cell signaling, the process of changing a signal into the form necessary to cause the cellular response. In prokaryotes, the process in which DNA is transferred from donor to recipient bacterial cells by an infecting bacteriophage

Question 12

Define Signaling cascade

Answer 12

I do not know

Question 13

Define Response

Answer 13

In signal transduction, the last stage in which the transduced signal causes the cell to change according to the signal and to the receptors on the cell. In neural signaling, the third and last component involving the action resulting from the integration of neural messages

Question 14

Define Transmembrane protein

Answer 14

An integral membrane that extends entirely through the plasma membrane

Question 15

Define Protein Kinases

Answer 15

Enzyme that transfers a phosphate group from ATP to one or more sites on particular proteins

Question 16

Define Phosphorylation cascade

Answer 16

A series of phosphorylation reactions catalyzed by a series of protein kinases

Question 17

Define Phosphorylation

Answer 17

The addition of a phosphate group to a molecule

Question 18

Define Protein phosphatases

Answer 18

An enzyme that, with a nucleosidase, breaks down a nucleoside to a nitrogenous base, a five carbon sugar, and a phosphate. In general, a phosphatase removes a phosphate group from a molecule

Question 19

Define Amplification

Answer 19

Occurs whenever a protein in a signaling pathway performs its function repeatedly, producing many copies of the next molecule in the pathway

Question 20

Define Amplification

Answer 20

Occurs whenever a protein in a signaling pathway performs its function repeatedly, producing many copies of the next molecule in the pathway

Question 21

Define Receptor tyrosine kinases (RTKs)

Answer 21

In signal transduction, a surface receptor with built-in protein kinase activity

Question 22

Define G-protein-coupled receptors (GPCRs)

Answer 22

In signal transduction, a surface receptor to a signal by activating a G protein

Question 23

Define First messenger

Answer 23

The extracellular signal molecule in signal transduction pathways controlled by G-protein- coupled receptors

Question 24

Define Effector

Answer 24

In signal transduction, a plasma membrane associated enzyme, activated by a G protein, that generates one or more second messengers. In homeostatic feedback, the system that returns the condition to the set point if it has strayed away. In nervous systems, non neuronal cells that respond to neurotransmitters released from neurons

Question 25

Define Second messengers

Answer 25

In particular signal transduction pathways, an internal, nonprotein signal molecule that directly or indirectly activates protein kinases, which elicit the cellular response

Question 26

Define cyclic AMP (cAMP)

Answer 26

In particular signal transduction pathways, a second messenger that activates protein kinases, which elicit the cellular response by adding phosphate groups to specific target proteins. cAMP functions in one of two major G-protein coupled receptor response pathways

Question 27

What is Inositol triphosphate (IP3)

Answer 27

A small, water soluble molecule that diffuses rapidly through the cytoplasm. Is a second messenger produced by breaking down a membrane phospholipid PIP2 with the enzyme phospholipase C

Question 28

What does Diacylglycerol (DAG) do?

Answer 28

activate protein kinases, which phosphorylate target proteins and produce that cellular response

Question 29

What is the primary effect of IP3 in animal cells

Answer 29

Activate ion channel proteins in the endoplasmic reticulum (ER), which release Ca2+ stored in the ER into the cytosol

Question 30

What is the effect of IP3 in plants

Answer 30

IP33 releases Ca2+ primarily from the large central vacuole and is involved in reactions that close plant stomata in response to a hormone signal

Question 31

Define Ligand-gated ion channels

Answer 31

A type of cell surface receptor that in response to a ligand binding, changes conformation, opening or closing an ion channel, thereby allowing or blocking ion movement through the channel

Question 32

Define Steroid hormone receptors

Answer 32

Internal receptor that turns on specific genes when it is activated by binging a specific steroid hormone

Question 33

Define Cross talk

Answer 33

Interaction by which cell signaling pathways communicate with one another to integrate their responses to cellular signals