Beetroot is a root vegetable with cells that contain a red pigment. Normally the pigment cannot pass out of the cells because it cannot diffuse through their cell surface membranes. An investigation was carried out into the effect of various chemicals on the permeability of the cell surface membranes of beetroot cells.
1cm3 samples were cut from the beetroot and washed in running water for 20 minutes to remove any pigment that was released from the damaged cells.
Five experiments were carried out. In each experiment, one cube of beetroot was placed in liquid P and one cube placed in liquid Q, and the results were observed.
Which row shows the correct results and conclusions?
Hi!
The question says the red pigment does not cross the cell membrane, thus the water should not turn red when the beetroot is placed solely in water that is just at 20 degrees. We can thus rule out row 1, 4 and 5.
Ethanol breaks down phospholipids and the cell membrane (thus the water will turn red). HCl will also break down the cell membrane (thus the water will turn red) and HCl lowers pH which can denature proteins. Row 3 is thus correct
Row 2 is not correct because ethanol doesn’t denature proteins.
Hope it helps!
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