Which statement correctly describes, why ions are unable to cross the plasma membrane without channel proteins?
Correct answer: B. They are unable to cross the hydrophobic tails of the lipid bilayer.
- A. They are unable to cross the hydrophilic phosphate heads of the lipid bilayer.
- B. They are unable to cross the hydrophobic tails of the lipid bilayer.
- C. They are unable to cross both the phosphate heads and fatty acid chains of the lipid bilayer.
- D. They are too big to cross the plasma membrane.
Explanation
Ions being are hydrophilic in nature and so are repelled by the hydrophobic interior of the plasma membrane which consists of hydrophobic fatty acid chains. This prevents the ions from freely crossing the membrane without any channel or carrier proteins.
Last updated
About Cell Structure and Function
Animal, plant, prokaryotic and eukaryotic cells are compared through their membranes, cell walls, nuclei and cytoplasmic organelles. The work includes the structures and functions of mitochondria, chloroplasts, ribosomes, endoplasmic reticulum, Golgi apparatus and lysosomes, as well as chromosome organization and the distinction between chromatin and chromosomes.
Practise Cell Structure and Function
2,478 free Cell Structure and Function MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.