20 first glossaries

Question 1

actin and myosin

Answer 1

proteins responsible for the muscle contraction

Question 2

active transport

Answer 2

energy-requiring translocation of a substance across a membrane against its electrochemical gradient

Question 3

afterhyperpolarization

Answer 3

hyperpolarization following an action potential

Question 4

agonist

Answer 4

a substance that have the same effect on a receptor as the mediator or transmitter

Question 5

albumin

Answer 5

largest protein fraction in the blood plasma, mainly responsible for the colloid osmotic pressure of the plasma

Question 6

aldo-sugar

Answer 6

sugar containing an aldehyde group (e.g. glucose, galactose)

Question 7

all-or-none response

Answer 7

amplitude of action potentials induced in excitable cells does not depend on the strength of the stimulus only on the membrane properties and on the ionic gradients

Question 8

alpha carbon atom

Answer 8

in organic acids the C-atom closest to the carboxyl group (see alpha-amino acids)

Question 9

alpha helix

Answer 9

helical secondary structure of proteins stabilized by H-bonds between peptide bonds located above each other

Question 10

alveoli

Answer 10

functional units of the lung, gases are exchanged through the walls of the alveoli

Question 11

anisotropic substance

Answer 11

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

Question 12

annulus fibrous

Answer 12

sheet of connective tissue separating the atria from ventricles and providing anchoring points for the valves

Question 13

antagonist

Answer 13

a substance that inhibits the effect of a mediator or transmitter at the receptor

Question 14

antibody

Answer 14

protein molecule produced by the lymphocytes that can specifically bind to antigens

Question 15

antigen

Answer 15

usually a large molecule or a smaller part of it that induces immunological response in the target organism

Question 16

apnea

Answer 16

a suspension or absence of breathing

Question 17

arteriole

Answer 17

muscular vessel connecting arteries and capillaries

Question 18

arteriovenous anastomosis

Answer 18

short vessels found especially in the skin, connecting arterioles and venules

Question 19

arteriovenous oxygen difference

Answer 19

difference between the partial pressure of oxygen in the arterial and venous blood flowing to and from an organ

Question 20

ATP

Answer 20

adenosine-triphosphate, energy-rich nucleotide used as a common energy source by all cells