periplasm
(ˈpɛrɪplæz(ə)m)
[mod. (De Bary 1881) f. Gr. περί around + πλάσµα anything formed: see plasm.]
1. Bot. The portion of the protoplasm in the sexual organs of the Peronosporeæ, left over after the differentiation of the sexual cells.
| 1887 tr. De Bary's Morphol. Fungi v. 134 The space between the oosphere and the wall of the oogonium continues to be filled with a slightly granular hyaline protoplasm, the periplasm, which may easily be overlooked. |
2. Microbiology. The region of a bacterial or other cell immediately within the cell wall, outside the plasma membrane. Hence periˈplasmic a.
| 1961 P. Mitchell in Goodwin & Lindberg Biol. Struct. & Function II. 590 Observations forced us to the conclusion that the glucose-6-phosphatase of intact Escherichia coli is enclosed in a region between the cell wall and the surface of the osmotic barrier component which we might appropriately call the ‘periplasm’. 1967 Science 16 June 1453/3 Some time ago Mitchell proposed that glucose-6-phosphatase activity is located in such a ‘periplasmic space’. 1974 Jrnl. Bacteriol. CXIX. 243/2 To determine whether the Hg(II)-reducing activity is present in the cytoplasm, the periplasm, or both. Ibid. 244/1 Alkaline phosphatase is one of the periplasmic enzymes. 1978 Sci. Amer. Oct. 74/2 The rat proinsulin would then ‘hitch-hike’ with the bacterial penicillinase into the periplasmic space, from which it could be extracted and then assayed with an antibody technique. |