Microscopy of Elodea pond weed, showing chloroplast and organelle movement 10/12/2019

Bright field

Live, unstained/unfixed

Andy

Firstly, an explanation about what is happening below:

From https://www.howplantswork.com/2010/04/25/chloroplast-movement-in-plant-cells-stirring-the-pot-avoiding-the-sun/

Movement of chloroplasts around the cell is called cyclosis or cytoplasmic streaming. Other organelles such as mitochondria are also streaming, along with the chloroplasts. This movement is on intracellular tracks called microfilaments, composed of actin proteins. The organelles are attached to the actin filaments by myosin, a motor protein. These proteins transform the chemical energy in ATP into mechanical energy leading to change in protein conformation and the protein molecule “walks” down the actin filament.

In leaf cells under bright sunlight, chloroplasts may have the ability to “move into the shade” of other chloroplasts, called photorelocation. Chloroplasts gather in areas irradiated with weak light to maximize photosynthesis (the accumulation response), and move away from areas irradiated with strong light to minimize damage of the photosynthetic apparatus (the avoidance response). The processes underlying these chloroplast movements can be divided into three parts: photoperception, signal transduction, and chloroplast movement.

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