The answer would be A—the molecular formula given is that of a long-chain, saturated fatty acid, which would be insoluble in water (i.e., hydrophobic).
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B describes carbohydrates, which can function as a storage of energy (e.g., starch or glycogen) or structural components (e.g., cellulose). The three examples just given are polymers of glucose, a monosaccharide; monosaccharide generally have the empirical formula CH2O; this is not the empirical formula of the given molecule (and, in any case, there are too few oxygen atoms for the number of carbon atoms), and so B is incorrect.
C describes an amino acid, likely an α-amino acid, which consist of a central, saturated carbon bonded to amino (—NH2) and carboxyl (—C(=O)OH) functional groups and a variable side chain, which determines the amino acid’s properties. Since the formula of an amino acid must contain nitrogen, which the formula given doesn’t have, the molecule couldn’t be an amino acid, and so C is incorrect.
D describes nucleic acids. Examples include DNA and RNA; nucleic acids and the nucleotide monomers that comprise them contain a nitrogenous base and a phosphate group. The given molecule’s formula has neither nitrogen nor phosphorus, and so cannot represent an amino acid, making D incorrect.
Parathyroid glands are the endocrine glands and are four in number. One superior and one inferior parathyroid glands are attached to each lateral lobe of the thyroid gland. These glands are found embedded in the tissues of the lateral lobes of the thyroid gland. During the removal of thyroid glands in patients, parathyroid glands may be mistakenly removed.
Cerebrum is in the most anterior part of our brain, fronting of the skull. It functions in sensory and neural processes. Cerebellum is found at the back of the skull. It functions in coordination, balance and muscular activity. Medulla oblongata connects from the spinal cord which controls heart and lungs. Pons is part of the brainstem which controls breathing and communication.
Graves' disease is an autoimmune disorder in which antibodies produced by your immune system stimulate your thyroid to produce too much T4. It's the most common cause of hyperthyroidism. Hyperfunctioning thyroid nodules (toxic adenoma, toxic multinodular goiter or Plummer's disease).
