本题目来源于试卷: Form and Function B.1 Carbohydrates & Lipids，类别为 IB生物学
[单选题]
Which of the following is only able to trigger a response in a cell by tn;kviln4o2-ek i g/7 bindingcc18ne1ma s y q+/t0bg t1c8emyq/bsgt a+0 1c no a receptor in the plasma membrane?
A. Insulin
B. Testosterone
C. Oestradiol
D. Progesterone
参考答案: A
本题详细解析:
Choice A is correct because insulin is a peptide hormone, whicvt*.:4+sq(ql o okk 3wjskas(h is polar so cannot directly pass through the plasma membrane. Instead it binds to receptors in the plasma membrane which triggers intracellular signalling pathways.Choices B, C and D are all incorrect, as they are all non-polar steroids so can diffuseq43 sojswk.koq:tsa+ (l(k v* through the plasma membrane and bind directly to receptors inside the cell, affecting gene expression.
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