Final answer:
Testosterone and estriol are synthesized from the lipid molecule cholesterol, which is a precursor to many steroid hormones.
Step-by-step explanation:
Testosterone and estriol, which are types of steroid hormones, are synthesized from the lipid molecule cholesterol. Cholesterol is the precursor to many steroid hormones and is a 19 carbon compound synthesized primarily in the liver. The process of synthesizing these hormones involves several steps, with pregnenolone being an important intermediate. The synthesis and secretion of testosterone are controlled by hormones LH and FSH, and in the blood, testosterone is carried by Testosterone Estradiol Binding Globulin or Sex Hormone Binding Globulin. In target tissues, testosterone is converted into its active form, dihydrotestosterone, by the enzyme NADPH-5-a-reductase.