A.p Biology Chapter 11

Front 1

adenylyl cyclase

Back 1

uh-den´-uh-lil) An enzyme that converts ATP to cyclic AMP in response to a signal.

Front 2

amplification

Back 2

The strengthening of stimulus energy during transduction.

Front 3

apoptosis

Back 3

(a-puh-to´-sus) A program of controlled cell suicide, which is brought about by signals that trigger the activation of a cascade of suicide proteins in the cell destined to die.

Front 4

biofilm

Back 4

A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation.

Front 5

cyclic AMP (cAMP)

Back 5

Cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (second messenger) in eukaryotic cells. It is also a regulator of some bacterial operons.

Front 6

cytoplasm

Back 6

(si´-to-plaz´-um) The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane.

Front 7

diacylglycerol (DAG)

Back 7

(di-a'-sil-glis'-er-ol) A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane.

Front 8

adenylyl cyclase

Back 8

uh-den´-uh-lil) An enzyme that converts ATP to cyclic AMP in response to a signal.

Front 9

epinephrine

Back 9

(ep'-i-nef'-rin) A catecholamine that, when secreted as a hormone by the adrenal medulla, mediates “fight-or-flight” responses to short-term stresses; also released by some neurons as a neurotransmitter; also known as adrenaline.

Front 10

amplification

Back 10

The strengthening of stimulus energy during transduction.

Front 11

G protein

Back 11

A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell.

Front 12

apoptosis

Back 12

(a-puh-to´-sus) A program of controlled cell suicide, which is brought about by signals that trigger the activation of a cascade of suicide proteins in the cell destined to die.

Front 13

gap junction

Back 13

A type of intercellular junction in animals that allows the passage of materials between cells.

Front 14

biofilm

Back 14

A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation.

Front 15

cyclic AMP (cAMP)

Back 15

Cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (second messenger) in eukaryotic cells. It is also a regulator of some bacterial operons.

Front 16

cytoplasm

Back 16

(si´-to-plaz´-um) The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane.

Front 17

diacylglycerol (DAG)

Back 17

(di-a'-sil-glis'-er-ol) A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane.

Front 18

epinephrine

Back 18

(ep'-i-nef'-rin) A catecholamine that, when secreted as a hormone by the adrenal medulla, mediates “fight-or-flight” responses to short-term stresses; also released by some neurons as a neurotransmitter; also known as adrenaline.

Front 19

G protein

Back 19

A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell.

Front 20

gap junction

Back 20

A type of intercellular junction in animals that allows the passage of materials between cells.

Front 21

glycogen

Back 21

(gli´-ko-jen) An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.

Front 22

growth factor

Back 22

(1) A protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells. (2) A local regulator that acts on nearby cells to stimulate cell proliferation and differentiation.

Front 23

inositol trisphosphate (IP3)

Back 23

(in-o´-suh-tol) A second messenger that functions as an intermediate between certain nonsteroid hormones and a third messenger, a rise in cytoplasmic Ca2+ concentration.

Front 24

ligand

Back 24

(lig´-und) A molecule that binds specifically to another molecule, usually a larger one.

Front 25

ligand-gated ion channel

Back 25

A protein pore in cellular membranes that opens or closes in response to A signaling chemical (its ligand), allowing or blocking the flow of specific ions.

Front 26

local regulator

Back 26

A secreted molecule that influences cells near where it is secreted.

Front 27

nitric oxide (NO)

Back 27

A gas produced by many types of cells that functions as a local regulator and as a neurotransmitter.

Front 28

protein kinase

Back 28

An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein.

Front 29

protein phosphatase

Back 29

An enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase.

Front 30

receptor tyrosine kinase

Back 30

A receptor protein in the plasma membrane, the cytoplasmic (intracellular) part of which can catalyze the transfer of a phosphate group from ATP to a tyrosine on another protein. Receptor tyrosine kinases often respond to the binding of a signaling molecule by dimerizing and then phosphorylating a tyrosine on the cytoplasmic portion of the other receptor in the dimer. The phosphorylated tyrosines on the receptors then activate other signal transduction proteins within the cell.

Front 31

scaffolding protein

Back 31

A type of large relay protein to which several other relay proteins are simultaneously attached, increasing the efficiency of signal transduction.

Front 32

second messenger

Back 32

A small, nonprotein, water-soluble molecule or ion, such as a calcium ion (Ca2+) or cyclic AMP, that relays a signal to a cell’s interior in response to a signaling molecule bound by a signal receptor protein.

Front 33

signal transduction

Back 33

The linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response.

Front 34

signal transduction pathway

Back 34

A series of steps linking a mechanical or chemical stimulus to a specific cellular response.

Front 35

testosterone

Back 35

A steroid hormone required for development of the male reproductive system, spermatogenesis, and male secondary sex characteristics; the major androgen in mammals.

Front 36

transcription factor

Back 36

A regulatory protein that binds to DNA and affects transcription of specific genes.

Front 37

transduction

Back 37

(1) A type of horizontal gene transfer in which phages (viruses) carry bacterial DNA from one host cell to another. (2) In cellular communication, the conversion of a signal from outside the cell to a form that can bring about a specific cellular response.

Front 38

yeast

Back 38

Single-celled fungus that reproduces asexually by binary fission or by the pinching of small buds off a parent cell; some species exhibit cell fusion between different mating types.