Self And The Phenomenon Of Life: A Biologist Examines Life From Molecules To Humanity

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“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity

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Glossary

AARS: see Aminoacyl-tRNA synthetase.

Action potential: Membrane potential in the axon that propagates from the

axon hillock (the origin of axon) to the synaptic ending (the tip of axon),

thus carrying with it the nerve impulse. Action potential is elicited by

EPSP (excitatory post-synaptic potential) when the depolarization exceeds

a threshold level. An action potential consists of an influx of sodium ion

followed by an efflux of potassium ion across the membrane. Once started,

an action potential propagates automatically.

Adaptation: Ability of an organism to change in order to survive in a new

environment. The theory of evolution provides a mechanism to explain

adaptation of a species.

Adaptive immunity: Immunity acquired during the lifetime of an animal.

Adenosine diphosphate (ADP): ATP minus one phosphate. It is a precursor

and breakdown product of ATP.

Adenosine triphosphate (ATP): An energy-rich molecule that performs

“work” inside the cell, including the synthesis of cellular components and

the movement of organelles. It also provides energy for the mobility of cells

and organisms, the latter through muscle contraction. Chemically, ATP

comprises an adenosine (the nucleobase adenine combined with ribose

sugar) attached to three phosphates.

ADP: see Adenosine diphosphate.

Allelopathy: Production of substances toxic to neighboring plants of different

species.

Allograft: Transplanting a tissue from one individual to another of the same

species.

Amino acid: The building block of a protein, consisting of an amino group, a

carboxylic acid group, and a variable side chain, the latter giving distinction

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