Describing tissues or organismsthat are not composed of discrete cells. Typi-cally,the cytoplasm is continuous throughout the tissue or organism,and contains manynuclei,demonstrating an equivalence to mul-ticellular structures. Examples are aseptatefungal...[继续阅读]

    Denoting a chromosome or fragment ofa chromosome that lacks a CENTROMERE.缺乏着丝粒的染色体或染色体片段。...[继续阅读]

    A carboxylicacid,CH3COOH,obtained by the oxidationof ethanol. Acetic acid is a component ofvinegar. This is obtained industrially by theaction of acetic acid bacteria,such as Aceto-bacter,on ethanol in wine waste.(乙酸) 一种羧酸,CH3COOH,通过乙醇氧化而获得。醋酸是食醋的成分之一...[继续阅读]

    A NEUROTRANS-MITTER found in both vertebrates and inver-tebrates at synapses in various parts of thenervous system and at NEUROMUSCULARJUNCTIONS. It can have either excitatory orinhibitory effects,depending on the location.For example,it is excitatory whe...[继续阅读]

    Any of various receptors that bind the neuro-transmitter acetylcholine at nerve synapses,neuromuscular junctions,or other effector or-gans. They are described as cholinergic re-ceptors,and fall into two broad categories.Nicotinic ( N ) acetylcholine recep...[继续阅读]

    An im-portant intermediate compound in cellmetabolism,particularly in the oxidation ofsugars,fatty acids,and amino acids,and incertain biosynthetic pathways. It is formed inthe mitochondrial matrix by the reaction be-tween pyruvate (from GLYCOLYSIS) andCO...[继续阅读]

    See acetylcholine.参阅acetylcholine。...[继续阅读]

    Any molecule or substance that tendsto release hydrogen ions (H+; protons). Inaqueous solutions,a free hydrogen ion rapidlycombines with a water molecule to form a hy-dronium ion (H3O+),also called an oxoniumion or hydroxonium ion. (However,it is con-vent...[继续阅读]

    A hypothesis pro-posed by R. Cleland,A. Hager and othersin around 1970 to explain cell wall expansionin growing plant cells. According to this,theplant hormone auxin stimulates a protonpump in the cells plasma membrane,whichpumps protons (H+) into the cel...[继续阅读]

    See staining. 参阅staining。...[继续阅读]