FILL IN 9) In passive cell transport, substances move from
concentrations to
concentrations.
10) in order for substances to diffuse, a
gradient must exist.
11) A concentration gradient is a
of concentrations between two regions.
12)
proteins or channel proteins are used to aid substances across the cell membrane in passive transport.
13) During passive transport, substances travel
the concentration gradient.
14) Facilitated diffusion uses
to help aid some substances across the cell membrane.
15) Cell membranes are
because they allow some substances to pass through more easily than others.
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