A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids is called what?

• A. Cholesterol
• B. Atherosclerosis
• C. Hypertension
• D. Pulse

Answer: (A)

Cholesterol is a lipid that forms an essential component of animal cell membranes and serves as the precursor for the synthesis of other biologically important steroids. In membranes, it sits among phospholipids, helping to modulate fluidity and stability so the membrane remains functional across temperature changes. As a precursor, it is converted into steroid hormones (such as estrogens, androgens, and corticosteroids) and bile acids, linking membrane structure to hormone and digest molecule production. The other terms describe diseases or a physiological measurement rather than a lipid with these roles—atherosclerosis is arterial plaque buildup, hypertension is high blood pressure, and pulse is heart rate. Therefore, cholesterol best fits the description.