Different Molecules

Question 1

competitive inhibition

Answer 1

reversible inhibition caused by a molecule that can bind to the same active site of an enzyme, receptor or transporter as the inhibited molecule

Question 2

ligand

Answer 2

signal molecule that can specifically bind to e receptor


Question 3

neurotransmitter (mediator)

Answer 3

signal molecule interacting with receptors in the postsynaptic membrane and usually modifying the membrane potential of the postsynaptic cell

Question 4

second messengers

Answer 4

small molecules whose concentration changes after the first messenger (signal) attaches to the membrane receptor


Question 5

neuromodulator

Answer 5

signal molecule changing neuronal functions; it usually has a broader and longer lasting effect than the neurotransmitters

Question 6

biogenic amines

Answer 6

signaling molecules synthesized in the body from amino acids by decarboxylization

Question 7

catecholamines

Answer 7

biogenic amines based on the catechol structure (aromatic six-carbon ring with two OH groups): dopamine (DA), norepinephrine (noradrenalin, NA), epinephrine (adrenaline, Adr)

Question 8

cAMP

Answer 8

cyclic adenosine monophosphate, signaling molecule


Question 9

dipole

Answer 9

a molecule having separate regions of net negative and net positive charge

Question 10

hydration

Answer 10

water molecules surround polar molecules and ions shielding off their charges and ensuring that they remain in the solution

Question 11

hydrophilic (lipophobic) and polar

Answer 11

polar or charged molecule that is able to interact with water molecules, thus can be dissolved in water


Question 12

nonpolar (hydrophobic, lipophilic)

Answer 12

substance lacking completely or partially separated charges that can be dissolved in lipids


Question 13

lipids

Answer 13

compounds soluble in nonpolar solvents


Question 14

phosphoglyceride

Answer 14

ubiquitous phosphorus-containing lipid; its structure is similar to that of the triglycerides, but one fatty acid is replaced by a phosphoric acid and a nitrogenous compound

Question 15

phospholipid

Answer 15

phosphorus-containing lipid


Question 16

triglycerides

Answer 16

lipid molecules composed of three fatty acid residues esterified to glycerol


Question 17

electrostatic interaction

Answer 17

attraction between oppositely charged ions or parts of larger molecules 


Question 18

elimination

Answer 18

inactivation of a signal molecule

Question 19

surface active agent

Answer 19

amphipathic molecule bearing both hydrophilic and hydrophobic groups

Question 20

surfactant

Answer 20

surface active agent lining the inner surface of the alveoli and decreasing surface tension

Question 21

surface active substance (amphipathic~, detergent~)

Answer 21

its molecules possess both hydrophilic and hydrophobic parts; they tend to line up at the border separating two different phases (lipid-water, water-air, etc.) with the hydrophilic and hydrophobic parts located in the appropriate phase

Question 22

phosphorylation

Answer 22

incorporation of a phosphate group into an organic molecule

Question 23

anisotropic substance

Answer 23

differentially transparent to polarized light depending on the plane of the light

Question 24

isotropic

Answer 24

optically homogenous material, transmission is independent of the plane of the polarized light