Question

How many of these hormones are lipid soluble?
Progesterone, Estrogen, Epinephrine, Cortisol, Norepinephrine, Thyroxine, Prolactin, Aldosterone.

Answer 1

Hint: Steroid hormones and iodothyronines are soluble in lipid and easily delivered to the cytoplasm through the cell membranes of target cells. In the cytoplasm, they bind to specific intracellular receptors (proteins) and form a complex of hormone receptors that enter the nucleus.

Complete answer:
Hormones are not non-nutrient chemicals which intercellular messenger and are produced in trace amounts. They are secreted into the bloodstream by endocrine glands or a special group of cells, directly or indirectly through the lymph.
On the basis of chemical nature hormones are divided into following categories
Steroid hormones- They are mainly composed of lipids derived from cholesterol. Testosterone, Estrogen, progesterone, Cortisol, Aldosterone etc.
Iodothyronines-thyroid hormones
Amino acid derivatives- The amine hormone is a derivative of the amino acid tyrosine. Examples-adrenaline, norepinephrine, epinephrine.
Peptide hormones-These hormones are composed of several amino acid residues and are represented by simple linear chains. Examples-Vasopressin and oxytocin.
Protein hormones- This hormone of hormones are also composed of many more amino acid residues. Represents primary, secondary and tertiary configurations. Example-Insulin and glucagon.
Steroid hormones and iodothyronines are soluble in lipid from the above options
Cortisol, Progesterone, Estrogen, Aldosterone are steroid hormones and thyroxine is an Iodothyronines and both these categories are soluble in lipids.

So, the correct option is (B) five.

Note:
> The hormone which interacts with the membrane bound receptors normally do not enter into the target cells, but generate secondary messengers. Peptide, polypeptide, protein hormones and catecholamines act through this mechanism.
> Lipid soluble hormones are capable of crossing the lipid bilayer hence they move into the cell in the cytoplasm and then they attach with intracellular receptors. Steroid hormones and iodothyronines come in this category.