Question

Which of the following hormones is NOT derived from cholesterol? A. Aldosterone B. Testosterone C. Oxytocin D. Progesterone

Short answer

Oxytocin

Step-by-step solution

Identify Cholesterol-Derived Hormones

Cholesterol is the precursor to steroid hormones. Steroid hormones include aldosterone, testosterone, and progesterone. These hormones are synthesized from cholesterol.

Analyze Each Hormone

Aldosterone, testosterone, and progesterone are identified as steroid hormones. Therefore, all three are derived from cholesterol. Oxytocin, on the other hand, is not a steroid hormone.

Determine the Correct Answer

Given that aldosterone, testosterone, and progesterone are all derived from cholesterol, the hormone that is NOT derived from cholesterol is oxytocin.

Key concepts

cholesterol-derived hormones

Cholesterol plays a crucial role in the synthesis of hormones essential for many bodily functions. These hormones are known as cholesterol-derived hormones. Cholesterol serves as the building block for these hormones. Through a series of biochemical steps, the body converts cholesterol into various steroid hormones.

Some key hormones derived from cholesterol include:

• Aldosterone: A hormone that helps regulate blood pressure and electrolyte balance.
• Testosterone: The primary male sex hormone important for developing male reproductive tissues and secondary sex characteristics.
• Progesterone: A hormone involved in the menstrual cycle, pregnancy, and embryogenesis.

Understanding cholesterol-derived hormones is vital because these hormones have far-reaching impacts on overall health.

steroid hormones

Steroid hormones are a special class of hormones derived from cholesterol. They are lipid-soluble, allowing them to pass easily through cell membranes to exert their effects inside cells. This is different from peptide hormones, like oxytocin, which are water-soluble and act on the cell surface.

Examples of steroid hormones include:

• Glucocorticoids: Hormones like cortisol that regulate metabolism and immune response.
• Mineralocorticoids: These hormones, such as aldosterone, control blood pressure and electrolyte balance.
• Sex Hormones: Including testosterone, estrogen, and progesterone, which are key to reproductive health.

Steroid hormones bind to specific receptors inside the cell, influencing gene expression and, consequently, a plethora of physiological functions.

hormone synthesis

Hormone synthesis is the process by which various hormones are produced in the body. For cholesterol-derived steroid hormones, synthesis begins with cholesterol.
Here's a simplified summary of hormone synthesis:

• Cholesterol is converted into pregnenolone in the mitochondria.
• Pregnenolone then serves as a precursor for progesterone and other steroid hormones.
• Steroid hormones are subsequently synthesized in specialized endocrine glands like the adrenal glands and gonads.

This synthesis process is controlled by various enzymes and regulatory proteins, ensuring that hormones are produced as needed.

Efficient hormone synthesis is essential for maintaining homeostasis and normal bodily functions.