Which is true about mediated transport of substances across cell membranes?
A. It involves a specific membrane protein that functions as a carrier molecule.
B. It always involves the movement of substances against a concentration gradient.
C. It is always directly coupled to the splitting of ATP molecules.
D. There is no limit to how fast it can occur as the concentration gradient becomes larger.
E. It is the main mechanism for transporting hydrophobic molecules across membranes.
A
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The space between the presynaptic and postsynaptic neurons is called the synaptic knob
a. True b. False Indicate whether the statement is true or false
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