Chloroplastus

Chloroplastus^[1] est organellum in cellulis nonnullorum eukarytorum, ubi photosynthesis fit.

Structura

Chloroplasti a cytoplasmate membrana duplici triplicive separantur. Intra chloroplastos autem inveniuntur vesiculae applanatae, thylacoides^[2] dictae, quorum omnium spatium internum, lumen dictum, commune est, atque in quorum membranis enzyma photosynthesis locantur. Apud Chlorophyta et Embryophyta, thylacoides in grana struuntur.^[3]

Inter plantas numeri chloroplastorum in cellulis differunt. Exempli gratia, chlorophytum Hydrodictyon singulos chloroplastos in unaquaque cellula possidet.^[4] Planta autem angiosperma Arabidopsis usque ad 120 chloroplastos in una cellula habere potest.^[5]

Evolutio

Chloroplasti apud plantas et algas inveniuntur, sed origo amborum per evolutionem haud eadem est.

Chloroplasti nempe plantarum a cyanobacterio orti sunt, ab eukaryoto quodam capto, haud autem digesto, sed retento atque per generationes permultas in organellum transmutato. Quod dicitur endosymbiosis primaria. Unde et chloroplasti plantarum duabus membranis, quae membranae externae internaeque cyanobacterii respondent, circumdantur.

E contra, chloroplasti harum algarum, quae ad plantas non pertinent, euglenarum scilicet, dinoflagellatorum et diatomearum, a planta capta, retenta et in organellum transmutata orti sunt, quod dicitur endosymbiosis secundaria. Unde et chloroplasti harum algarum tribus membranis circumdantur, quarum duae membranis chloroplasti plantae respondent, tertia vero membranae illius plantae captae retentaeque.^[6]

Bibliographia

Keeling, Patricius J. 2004. "Diversity and evolutionary history of plastids and their hosts." American Journal of Botany 91 (10): 1481–1493.

Notae

↑ ‘Chloroplastus’: vide diagnosin Cosmarii planogranati a v. cl. Croasdale scriptam, in libro Botanical Latin (W. T. Stearn, ed. 4a, 1992) citatam
↑ ‘Thylacoides’: vide diagnosin Chlorogonii complexi, ubi dicitur: “Lamellae thylacoidum tubulares...”. Takashi Nakada, Tomoyoshi Soga, Masaru Tomita & Hisayoshi Nozaki (2010) Chlorogonium complexum sp. nov. (Volvocales, Chlorophyceae), and morphological evolution of Chlorogonium. European Journal of Phycology, 45 (1): 97–106.
↑ Shimoni, Eyal, Rav-Hon, Ophir, Ohad, Isaac, Brumfeld, Vlad & Reich, Ziv (2005) Three-Dimensional Organization of Higher-Plant Chloroplast Thylakoid Membranes Revealed by Electron Tomography. The Plant Cell, 17 (9): 2580–2586.
↑ Prescott, G.W. (1961) Algae of the western Great Lakes area. Dubuque (Iova): Wm. C. Brown Company Publishers. ISBN 0-697-04552-8 LCCN 61-18674
↑ Crumpton-Taylor, Mathildis, Grandison, Scott, Png, Kenneth M.Y., J. Bushby, Andreas & Smith, Alicia M. (2012) Control of Starch Granule Numbers in Arabidopsis Chloroplasts. Plant Physiology, 158 (2): 905–916.
↑ Keeling, op. cit.

[1] ‘Chloroplastus’: vide diagnosin Cosmarii planogranati a v. cl. Croasdale scriptam, in libro Botanical Latin (W. T. Stearn, ed. 4a, 1992) citatam

[2] ‘Thylacoides’: vide diagnosin Chlorogonii complexi, ubi dicitur: “Lamellae thylacoidum tubulares...”. Takashi Nakada, Tomoyoshi Soga, Masaru Tomita & Hisayoshi Nozaki (2010) Chlorogonium complexum sp. nov. (Volvocales, Chlorophyceae), and morphological evolution of Chlorogonium. European Journal of Phycology, 45 (1): 97–106.

[3] Shimoni, Eyal, Rav-Hon, Ophir, Ohad, Isaac, Brumfeld, Vlad & Reich, Ziv (2005) Three-Dimensional Organization of Higher-Plant Chloroplast Thylakoid Membranes Revealed by Electron Tomography. The Plant Cell, 17 (9): 2580–2586.

[4] Prescott, G.W. (1961) Algae of the western Great Lakes area. Dubuque (Iova): Wm. C. Brown Company Publishers. ISBN 0-697-04552-8 LCCN 61-18674

[5] Crumpton-Taylor, Mathildis, Grandison, Scott, Png, Kenneth M.Y., J. Bushby, Andreas & Smith, Alicia M. (2012) Control of Starch Granule Numbers in Arabidopsis Chloroplasts. Plant Physiology, 158 (2): 905–916.

[6] Keeling, op. cit.

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