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Chloroplasts, containing thylakoids, visible in the cells of Ptychostomum capillare, a type of moss. A chloroplast (/ ˈ k l ɔːr ə ˌ p l æ s t,-p l ɑː s t /) [1] [2] is a type of organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells.
A wheeled buffalo figurine—probably a children's toy—from Magna Graecia in archaic Greece [1]. Several organisms are capable of rolling locomotion. However, true wheels and propellers—despite their utility in human vehicles—do not play a significant role in the movement of living things (with the exception of certain flagella, which work like corkscrews).
A plant cell wall was first observed and named (simply as a "wall") by Robert Hooke in 1665. [3] However, "the dead excrusion product of the living protoplast" was forgotten, for almost three centuries, being the subject of scientific interest mainly as a resource for industrial processing or in relation to animal or human health.
Like mitochondria, chloroplasts have a double-membrane envelope, called the chloroplast envelope, but unlike mitochondria, chloroplasts also have internal membrane structures called thylakoids. Furthermore, one or two additional membranes may enclose chloroplasts in organisms that underwent secondary endosymbiosis , such as the euglenids and ...
Two sections of chloroplast flow are observed with the aid of a microscope. These sections are arranged helically along the longitudinal axis of the cell. [8] In one section, the chloroplasts move upward along one band of the helix, while in the other, the chloroplasts move downwardly. [8] The area between these sections are known as ...
Whether Mg 2+ is able to move into and out of chloroplasts after this initial developmental phase has been the subject of several conflicting reports. Deshaies et al. (1984) found that Mg 2+ did move in and out of isolated chloroplasts from young pea plants, [ 93 ] but Gupta and Berkowitz (1989) were unable to reproduce the result using older ...
“We feel bad that this happened,” she adds. Liu says that she and her research team have submitted a correction to the journal, which should be published soon. But this may not change the ...
This process is in contrast to passive transport, which allows molecules or ions to move down their concentration gradient, from an area of high concentration to an area of low concentration, without energy. Active transport is essential for various physiological processes, such as nutrient uptake, hormone secretion, and nerve impulse transmission.