It can't enter cells because it's too big and it's too water soluble so it can't go through cell membranes.

它的分子太大了所以无法进入细胞,而且还是水溶性的,所以它也无法穿过细胞膜

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So inside the cell mostly water, outside the cell mostly water, but I need to separate my water from the water outside.

那么细胞内大多是水,细胞外大多也是水,但我需要将体内的和体外的水隔离开

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There's lipid chains in between so cell membranes are lipid rich layers that can exist in water.

脂质链在两者中间,所以细胞膜是富含脂类的膜层,并可以稳定存在于水中

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