The cytoplasmic membrane is termed "semi-permeable" because some substances, like water and alcohols, can pass freely through while others, like sugars, amino acids, and ions, cannot. What molecular characteristics largely determine whether or not a substance can pass through the membrane?

Question

Andrea

Biology

11 May, 09:50

The cytoplasmic membrane is termed "semi-permeable" because some substances, like water and alcohols, can pass freely through while others, like sugars, amino acids, and ions, cannot. What molecular characteristics largely determine whether or not a substance can pass through the membrane?

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Answers (1)

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Nylah Buckley · Answer 1

The correct answer is - size and hydrophobicity

Explanation:

The cell membrane is a semi-permeable membrane which means it only allows the transport of selective molecules across it. Some molecules can cross the membrane freely but some require transporters.

The passage of molecules is highly dependent on the size and hydrophobicity of the molecule. The molecule which is smaller in size, hydrophobic and neutral can freely diffuse through the plasma membrane.

The molecule which is hydrophilic, large and charged requires transporter protein to be transported. Therefore the correct answer is size and hydrophobicity.