Testosterone is responsible for secondary male characteristics, estradiol for secondary female characteristics and menstrual cycle control, and progesterone prepares the uterus for the implantation of a fertilized egg.

Malfunctioning adrenal cortex, as seen in Addison’s disease, leads to hypoglycemia, weakness, and increased stress susceptibility. Treatment involves glucocorticoids and mineralocorticoids.

Glucocorticoids control carbohydrate metabolism, modulate inflammatory reactions, and respond to stress, while mineralocorticoids regulate water and salt excretion by the kidneys.

Hormones act as intercellular messengers, and they vary in chemical nature. Examples include steroids (estrogens, androgens), polypeptides (insulin, endorphins), and amino acid derivatives (epinephrine, norepinephrine). Hormones help maintain biological balance, as seen in insulin and glucagon regulating blood glucose levels.

While proteins are synthesized by various RNA molecules, the instructions for protein synthesis are encoded in DNA. DNA provides the genetic information used by RNA in the cell’s protein synthesis process.

DNA serves as the chemical basis of heredity, maintaining species identity over time. It undergoes self-duplication during cell division, transferring identical DNA strands to daughter cells.

Adenine pairs with thymine, and cytosine pairs with guanine through hydrogen bonds in DNA. RNA has a single-stranded helical structure, with messenger RNA (m-RNA), ribosomal RNA (r-RNA), and transfer RNA (t-RNA) serving different functions.

The primary structure of nucleic acids refers to the sequence of nucleotides in the chain, while the secondary structure, proposed by Watson and Crick, reveals a double-strand helix structure for DNA with complementary base pairs held by hydrogen bonds.

A nucleoside is formed by attaching a base to the 1’ position of a sugar. Nucleotides are created when a nucleoside links to phosphoric acid at the 5’-position of the sugar, and nucleotides join through phosphodiester linkages.