{"id":643,"date":"2023-12-05T17:11:49","date_gmt":"2023-12-05T17:11:49","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=643"},"modified":"2023-12-05T17:11:50","modified_gmt":"2023-12-05T17:11:50","slug":"page-126","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=643","title":{"rendered":"Page 126"},"content":{"rendered":"\n

Depending on that, whether the basic genetic material (DNA) is
located \u201cfreely\u201d in cytoplasm or in a well defined nucleus encircled by a
double membrane, the cells are divided into prokaryotic (protocists) and
eukaryotic (eucists). Bacteria and unicellular blue-green algae are typical
prokaryotic cells. All the other cells \u2014 either independently existing, or
included in the composition of multicellular organisms \u2014 are eukaryotic.
Irrespective of some differences and peculiarities the cells possess
similar internal organization. Each cell possesses an envelope, nucleus or
nuclear equivalent (nucleoid) and cytoplasm, which plays the role of \u201cinternal
skeleton\u201d of the cell. In the cytoplasm (Fig. 2\u201353) there are situated cell
organelles (from Latin organella<\/em> \u2014 organ, instrument) connected in a common
system. Some of them perform also autonomous functions.<\/p>\n\n\n\n

image<\/p>\n\n\n\n

Figure 2\u201353. Cytoplasmic structure in a cell of onion root (Allium \r\ncepa<\/em>), fixed through OsO\u2084. The dark particles represent ribosomes \r\n(After Frey-Wissling and M\u00fchlethaler, 1965).<\/pre>\n\n\n\n
Cell Wall and Cell Envelope<\/strong><\/p>\n\n\n\n
The cell walls and cell envelope separate the cells from the surroundings or
from the other cells in multicellular organisms, thus creating conditions
necessary for carry out of the life processes in them. They are peculiar
biological filters, selectively permeable for inorganic and organic
substances necessary for their metabolism. They also excrete the waste
products.
In 1931 W. Lewis discovered the phenomenon pinocytosis (Greek:
pino<\/em> \u2014 drink and k\u00fdtos<\/em> \u2014 cell) considered to be one of the basic
mechanisms of penetrating into the cells of high-molecular compounds \u2014
proteins, carbohydrates, sugar-protein complexes, etc. It was shown
diagrammatically, that this process is realized through forming bubbles by
making concave the cell membrane. Once formed, the bubbles pass in the
cytoplasm and are transported in it (Fig. 2\u201354 A). Latter on pinocytosis was<\/p>\n","protected":false},"excerpt":{"rendered":"
Depending on that, whether the basic genetic material (DNA) islocated \u201cfreely\u201d in cytoplasm or in a well defined nucleus encircled by adouble membrane, the cells are divided into prokaryotic (protocists) andeukaryotic (eucists). Bacteria and unicellular blue-green algae are typicalprokaryotic cells. All the other cells \u2014 either independently existing, orincluded in the composition of multicellular organisms […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[6],"tags":[],"class_list":["post-643","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/643","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=643"}],"version-history":[{"count":1,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/643\/revisions"}],"predecessor-version":[{"id":653,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/643\/revisions\/653"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=643"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=643"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=643"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}