Membranous organelle directed flow

A number of other organelles stud the cytoplasm. Mitochondria are the power plants of the cell they specialize in the chemical reactions that turn calorie-laden nutrient molecules into forms of chemical energy that the cell can use directly. Mitochondria have two membranes. The controlled burning of nutrient molecules generates a difference between the acidity of the space enclosed by the inner membrane and that enclosed between the inner and outer membranes. The controlled flow of acid between the two compartments generates energy, like the flow of water over a dam generates electrical power. 

Question What controls the directed flow of membranous organelles ... 

The individual pathways of carbohydrate metabolism in plants overlap extensively they share pools of common intermediates, including hexose phosphates, pentose phosphates, and triose phosphates. Transporters in the membranes of chloroplasts, mitochondria, amyloplasts, and peroxisomes mediate the movement of sugar phosphates between organelles. The direction of metabolite flow through the pools changes from day to night. 

In essence, any cell is simply a compartment with a watery interior that is separated from the external environment by a surface membrane (the plasma membrane) that prevents the free flow of molecules in and out of cells. In addition, as we ve noted, eukaryotic cells have extensive internal membranes that further subdivide the cell into various compartments, the organelles. The plasma membrane and other cellular membranes are composed primarily of two layers of phospholipid molecules. These bipartite molecules have a water-loving (hydrophilic) end and a water-hating (hydrophobic) end. The two phospholipid layers of a membrane are oriented with all the hydrophilic ends directed toward the inner and outer surfaces and the hydrophobic ends buried within the Interior (Figure 1-13). Smaller amounts of... 

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