unit 4 study guide

Question 1

signal transduction

Answer 1

the translation of extracellular signals into specific responses by a cell

Question 2

taxis

Question 3

chemotaxis

Question 4

homeostasis

Question 5

ligands

Answer 5

a chemical signal; a molecule that is released by a cell & then binds to a receptor protein

Question 6

reception

Answer 6

ligand binding changes shape of receptor, which sets off chain reaction in cell

Question 7

intracellular receptors

Answer 7

bind to ligands inside a cell

Question 8

cell surface receptor

Answer 8

located in/on the cell membrane + binds to ligands on the surface of the cell

Question 9

transduction

Answer 9

molecules activate one another to send the signal from the receptor to target molecules in the cell

Question 10

secondary messenger

Answer 10

non-protein molecules, pass along a signal that was initiated by the receptor + ligand

Question 11

signal cascade

Answer 11

a series of enzyme driven reactions in which the product of 1 reaction activates the next

Question 12

phosphorylation cascade

Answer 12

the activation of an enzyme by the addition of a phosphate group

Question 13

autocrine

Answer 13

a cell produces a response to its own signal

Question 14

juxtacrine

Answer 14

a cell signals an adjacent cell that it is physically touching

Question 15

paracrine

Answer 15

a cell signals a nearby cell

Question 16

endocrine

Answer 16

a signal that is sent from one part of the body to another

Question 17

response

Answer 17

occurs in either cytoplasm or nucleus, final step in signal transduction

Question 18

metabolism response

Answer 18

type of cytoplasmic response, regulation of the early stages of cellular respiration

Question 19

cytoplasmic response

Answer 19

regulation of an enzyme or process in the cytoplasm

Question 20

nuclear response

Answer 20

transcription factors bind to genes to initiate or inhibit protein synthesis

Question 21

quorum sensing

Answer 21

bacteria monitor density of population until it reaches its threshold, at whic point all bacteria will change behavior/gene expression in response

Question 22

apoptosis

Answer 22

programmed cell death, can be the response of a signal transduction

Question 23

G-protein linked receptor

Answer 23

a large family of cell surface receptors, transmit signals inside a cell through a G-protein

Question 24

catalytic (enzyme-linked) receptor

Question 25

ligand-gated ion channel

Answer 25

can open in response to the binding of a ligand, able to open + close, allows ions to cross the membrane without having to touch the hydrophobic core

Question 26

negative feedback pathway

Question 27

positive feedback pathway

Question 28

feedback inhibition