The question specifies that thyroid-stimulating hormone (TSH) binds to cell surface receptors. This is in contrast to steroid hormones, which are derived from cholesterol and bind to intracellular receptors before moving to the nucleus to directly modify gene expression. Remember, steroids are fat soluble and thus have no need for a receptor on the cell surface; they are small and nonpolar, allowing them to cross the membrane freely. In contrast, peptide hormones are not able to traverse the lipid membrane, and thus require a surface receptor.

One commonality between all steroid hormones is that they are active in the nucleus. Due to their nonpolar design, these hormones can pass through phospholipid membranes. All steroid hormones can be derived from cholesterol. This class of hormones includes testosterone, estrogen, progesterone, and aldosterone.

The other two classes of hormones are peptide hormones and tyrosine derivatives. Peptide hormones are proteins, synthesized from amino acids residues, and are unable to cross the lipid membrane due to their size and polarity. Thyroid-stimulating hormone is a peptide hormone. Tyrosine derivatives are modified from molecules of the amino acid tyrosine, making them polar. Thyroid hormones and epinephrine are derived from tyrosine.

Glucose is not used to synthesize hormones.

It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. T4, known as tetraiodothyronine, and the catecholamines are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.

Hormones that bind to cytoplasmic receptors are nonpolar. Nonpolar hormones can pass through the nonpolar phospholipid bilayer of the cell membrane, while polar hormones cannot pass through the cell membrane and must bind to receptors on the surface of the cell. Steroids are nonpolar hormones while peptide hormones are polar hormones. Estrogen is a steroid, and is therefore the correct answer.

Transmembrane receptors are only needed for molecules that CANNOT pass through the cell membrane. Growth hormone, insulin, calcitriol, and secretin are examples of molecules that cannot pass the cell membrane. Their respective receptors are transmembrane receptors. Cortisol, on the other hand, is a cholesterol derivative and can pass through the cell membrane due to its hydrophobic elements. Therefore cortisol receptors are not transmembrane receptors.

Thyroid hormone is one the few hormones that are derived from a single amino acid, in this case tyrosine. Amino acids (and subsequently their derivatives) are mostly hydrophilic, and are unable to pass through the cell membrane. They must bind to surface receptors in order to initiate their effects on the cell.

Understanding the difference between peptide hormones and glucocorticoids is important in answering this question. Peptide hormones function through cell surface receptors, and usually subsequent G-protein regulated signal amplification. Glucocorticoid hormones generally function by modifying gene expression directly in the nucleus. Generally, peptide hormones end with the suffix -in, while glucocorticoids end with -one or -en. Using this information we see that renin would be a peptide hormone and would therefore function through cell surface receptors.

Peptide hormones rely on a secondary messager system, such as cyclic AMP, to perform their functions on target cells/organs. Of the available answer choices, insulin, calcitonin, and parathyroid hormone (PTH) are peptide hormones, and are therefore incorrect.

Steroid hormones have intracellular receptors and can enter cells directly to cause changes in transcription rates, which result in their effects. Estrogen is a steroid hormone, and thus does NOT use a secondary messanger system.

Somatotropin, or human growth hormone, is responsible for both bone and cartilage growth. It is the main factor in human growth, up until puberty.

Calcitonin decreases blood calcium level. All other answer choices correctly pair a hormone with its function.