本题目来源于试卷: Form and Function B.3 Membranes & Membrane Transport,类别为 IB生物学
[单选题]
Which statement correctly0dr nznje443 a6 5hehc d2pd s1x /wg4(qmq hih;escribes the cell membrane structure?
A. A phospholipid bilayer where phosphate heads align facing each other and lipid tails point away.
B. A phospholipid bilayer where lipid tails align facing each other and phosphate heads point away.
C. A phospholipid bilayer where proteins line the outer layer and phospholipids line the inner layer.
D. A layer of phospholipids with phosphate heads facing outside the cell and lipid tails facing the cell cytoplasm.
参考答案: B
本题详细解析:
A cell membrane is formedj/ ;sa pjllfyj63yyd 7c0 z;x9 of two layers of phospholipids whereby hydrophilic phosphate heads face the cytoplasm of the cell (cell interior) and the cell's environment (exterior) while the hydrophobic lipid tails face each other and form the interior of the membrane.Having lipid tails pointing away (Choice A) is nof dzly;y3c/ xsa9y7jl; j06pjt a valid choice since lipid tails are hydrophobic and cannot face the cell's aqueous interior and exterior. Proteins are embedded in the membrane and do not line the outer layer (Choice C). The cell membrane is a bilayer and not just a monolayer (Choice D).
|