Nucleotides and Nucleic Acids

Nucleotides and Nucleic Acids

• Nucleotides are biomolecules that play an important role in energy and information transfer.
• Single nucleotides include ATP, ADP, and cyclic AMP.
• Nucleic acids, such as RNA and DNA, store and transmit genetic information.
• The sugar of one nucleotide links to the phosphate of the next, creating a chain of alternating sugar-phosphate chains, or backbone, which is the same for every nucleic acid molecule.
• Nucleotides chains form strands of DNA and RNA.

Protein Structure

• Amino acids can link together by peptide bonds to form oligopeptides, polypeptides, and proteins.
• Primary structure: The sequence of amino acids in a peptide chain.
• The 20 amino acids can create an almost infinite number of combinations.
• Secondary structure: Created primarily by hydrogen bonds between adjacent chains or loops.
• Tertiary structure: The three-dimensional shape of a protein.
• Quaternary structure: Multiple subunits combine with non-covalent bonds.

DNA, RNA, and Nucleotide Pairing

• RNA: A single-strand nucleic acid with ribose as the sugar in the backbone, and four bases: adenine, guanine, cytosine, and uracil.

Free Radicals

• A molecule or ion with unpaired electrons that will try to "steal" an electron from another molecule.

Chemical Bonds

• Covalent bonds: Strong bonds formed when adjacent atoms share one or more pairs of electrons to form molecules.
• Ionic bonds: Strong bonds between cations and anions (opposite charges attract).
• Hydrogen bonds: An attractive force between a hydrogen atom and a nearby fluorine, oxygen, or nitrogen.
• Van der Waals forces: Attraction between the nucleus of any atom and the electrons of nearby atoms.

Biomolecules

• Carbohydrates: Most abundant, simple sugars (monosaccharides/disaccharides), and complex polymers (polysaccharides).
• Lipids: Made up of C and H, non-polar, and structurally diverse (triglycerides, phospholipids, eicosanoids, steroids).
• Proteins: Made up of amino acids, with a versatile structure and function.

Hormones

• Hormones are cell-to-cell communication molecules.
• Made in glands or cells, secreted into the blood for transport, and exert their effect on distant target tissue receptors.
• Activate physiological responses, controlling rates of enzymatic reactions, transport of ions or molecules across cell membranes, and gene expression and protein synthesis.
• Classifications: Peptide or protein hormones, steroid hormones, and amine hormones.

Hypothalamus and Pituitary Gland

• Posterior pituitary releases vasopressin (ADH) and oxytocin.
• Hypothalamus and anterior pituitary gland are connected through the hypothalamic hypophyseal portal system.
• The hypothalamic hypophyseal portal system directs trophic hormone delivery from the hypothalamus to the anterior pituitary through blood vessels.