AEMCA Practice Exam

What is direct gene activation?

1. Interactions between cell membranes and amino acid hormones.

2. Effects of steroid hormones on specific target organs.

3. Reactions between hormones and blood sugar levels.

4. Inhibition of insulin production.

The correct answer is: Effects of steroid hormones on specific target organs.

Direct gene activation refers to the process by which certain hormones, particularly steroid hormones, can enter target cells and bind to specific receptors within the nucleus. When these steroid hormones bind to their receptors, they initiate a series of molecular events that lead to the activation of specific genes. This results in the transcription of messenger RNA (mRNA), which ultimately dictates the production of proteins that carry out functions in the cell, thereby influencing physiological processes. Steroid hormones, such as cortisol, estrogen, and testosterone, are lipophilic, allowing them to pass through cell membranes easily to reach their intracellular receptors. This direct interaction with gene transcription is what characterizes direct gene activation, distinguishing it from other types of hormone action that may require second messengers or other signaling pathways. The understanding of this mechanism is essential for comprehending how hormones regulate various bodily functions at the genetic level, impacting growth, metabolism, reproduction, and other critical processes.