Chapter 25, Problem 1MCQ

Summary Introduction

Introduction:

Testosterone and estrogen are examples of steroid hormones. The majority of steroid hormones are synthesized from cholesterol. Steroid hormones can easily cross the cell membrane without the involvement of secondary messenger.

Answer to Problem 1MCQ

Correct answer:

The effect of the water-soluble peptide hormone such as insulin is quicker than that of the steroid hormone such as estrogen because steroid hormones either stimulate or inhibit the process of protein synthesis which takes time. Hence, the correct answer is option b.

Explanation of Solution

Reason for correct answer:

Option b. is given as, “steroid hormones stimulate or inhibit protein synthesis, which takes time.”

Most of the steroid hormones are lipid soluble and are derived from cholesterol. The effect of water-soluble peptide hormones is quicker as compared to steroid hormones because the steroid hormones enter the nucleus and bind to a membrane receptor which is associated with the DNA. The hormone either stimulates or inhibits the process of protein synthesis. The response of steroid is slower as compared to water-soluble hormone because new proteins are needed to be produced prior to the effect of the hormone.

Reason for incorrect answer:

Option a. is given as, “peptide hormones are synthesized within target cells, whereas steroid hormones must travel to target cells.”

Steroid hormones need to travel to target cells, but they cannot show their effect till new proteins are produced or stopped. Hence, option a. is incorrect.

Option c. is given as, “steroid hormones cannot pass through the cell membrane.”

Steroid hormones can easily cross the cell membrane as they are lipid soluble and do not require the help of a secondary messenger. Hence, option c. is incorrect.

Option d. is given as, “All of these are correct.”

Steroid hormones either stimulate or inhibit the process of protein synthesis prior to their effect on the target cell. Hence, option d. is incorrect.

Hence, the options a., c., and d. are incorrect.

Conclusion

Steroid hormones response is slower as compared to water-soluble peptide hormones because these hormones either stimulate or inhibit the process of protein synthesis prior to their effect on the target cell. Thus, the correct option is b.