BCM 1.4 - Water, Micronutrients, Transition Metals, and Free Radicals

Vocabulary practice flashcards covering the chemical properties of water, micronutrient classes, fat- and water-soluble vitamins, macro- and microminerals, transition metals, and free radicals based on the Biochemistry Module 2 lecture notes.

Dipole Moment (Water)

A separation of charges in a water molecule caused by an unequal distribution of electron density, resulting from oxygen's higher electronegativity relative to hydrogen and a bent molecular geometry with a bond angle of $104.5^\circ$.

Dielectric Constant

A measure of the capacity of a solvent to reduce the attractive forces between oppositely charged ions, making water a universal solvent due to its high value.

Micelles

Spherical structures formed by amphipathic molecules in an aqueous medium at a critical concentration, where hydrophobic nonpolar tails direct inward away from water and hydrophilic polar heads face outward.

Heat of Vaporization

The amount of energy required to vaporize one mole of liquid at a pressure of one atmosphere.

Heat Capacity

The energy that must be added or removed to change the temperature of a substance by one degree Celsius.

Transition Metals

Chemical elements in the d-block of the periodic table that form bonds using electrons from more than one shell, enabling them to change oxidation states and function as essential enzyme cofactors in redox reactions.

Free Radicals

Unstable, cell-damaging atoms or molecules containing one or more unpaired outer-shell electrons (e.g., $\text{OH}^\bullet$) that stabilize themselves by stealing electrons from other biological molecules.

Retinoids

A family of Vitamin A-related compounds comprising retinol, retinal (retinaldehyde), retinoic acid, and $\beta$-carotene.

Cholecalciferol

Vitamin $\text{D}_3$, synthesized in the skin from 7-dehydrocholesterol following ultraviolet sunlight exposure or obtained from animal products, which is more effective at raising blood vitamin D levels than ergocalciferol.

Rickets

A manifestation of Vitamin D deficiency in children characterized by poor bone mineralization, bowlegs, knock-knees, pigeon breast, frontal bossing of the skull, and beading of the ribs.

Osteomalacia

A manifestation of Vitamin D deficiency in adults characterized by bone demineralization, rheumatic pain, waddling gait, and tetany.

Tocopherols

Lipid-soluble compounds ($\alpha, \beta, \gamma, \delta$) contributing to Vitamin E activity that function as primary antioxidants to prevent the peroxidation of polyunsaturated fatty acids (PUFA) in cell membranes.

Phylloquinone

Naturally occurring Vitamin $\text{K}_1$ found in green plants that acts as a cofactor for hepatic carboxylase to form $\gamma$-carboxyglutamic acid (Gla) residues on blood-clotting proteins.

Menaquinone

Fat-soluble Vitamin $\text{K}_2$, formed as a result of bacterial action in the intestinal tract.

Menadione

A water-soluble synthetic Vitamin $\text{K}_3$ derivative lacking a long side chain, making it twice as biologically potent on a weight basis as naturally occurring Vitamin $\text{K}_1$ or $\text{K}_2$.

Thiamine Pyrophosphate (TPP)

The active coenzyme form of Vitamin $\text{B}_1$ required for the oxidative decarboxylation of pyruvate and other $\alpha$-ketoacids, as well as for the transketolase reaction in the pentose phosphate shunt.

Dry Beriberi

A clinical form of Vitamin $\text{B}_1$ (thiamine) deficiency characterized by peripheral neurological manifestations including headache, insomnia, dizziness, and muscle wasting.

Wet Beriberi

A clinical form of Vitamin $\text{B}_1$ (thiamine) deficiency characterized by cardiovascular involvement with edema and effusions.

Cheilosis

A clinical symptom of Vitamin $\text{B}_2$ (riboflavin) deficiency manifested as swelling and fissuring of the lips.

Pellagra

A deficiency disease resulting from a lack of Vitamin $\text{B}_3$ (niacin) or its precursor tryptophan, characterized by the triad of dermatitis, dementia, and diarrhea.

Pyridoxal Phosphate (PLP)

The primary active coenzyme form of Vitamin $\text{B}_6$ involved in amino acid transamination, glycogen phosphorylase activity, heme synthesis, and neurotransmitter formation.

Biotin

Vitamin $\text{B}_7$, a monocarboxylic acid that acts as a coenzyme for enzymatic carboxylation reactions involving the addition or removal of carbon dioxide ($\text{CO}_2$).

Tetrahydrofolate (THFA)

The active reduced coenzyme form of Vitamin $\text{B}_9$ (folate) that functions as a carrier of single-carbon units essential for purine/pyrimidine synthesis, amino acid metabolism, and heme formation.

Intrinsic Factor

A glycoprotein present in gastric secretion required for the intestinal absorption of Vitamin $\text{B}_{12}$ (cobalamin) by forming a complex that binds to specific receptors in the ileum.

Ascorbic Acid

Vitamin C, a hexose derivative and water-soluble antioxidant required for the hydroxylation of proline and lysine in collagen synthesis, as well as enhancing intestinal iron absorption.

Scurvy

A Vitamin C deficiency disease characterized by follicular hyperkeratosis, swollen gums, loose teeth, impaired wound healing, and bleeding into skin and mucous membranes.

Trabeculae

Crystalline structures in the ends of long bones containing the exchangeable pool of skeletal calcium (about $1\%$ of total skeletal calcium) that can be mobilized to maintain calcium homeostasis.

Ferrous Ion ($\text{Fe}^{2+}$)

The reduced form of iron that is soluble in water across all pH levels, more reactive, and better absorbed by intestinal mucosal cells compared to the oxidized ferric ion ($\text{Fe}^{3+}$).

Divalent Metal Transporter 1 (DMT1)

An intestinal apical membrane transporter protein that transports free ferrous iron ($\text{Fe}^{2+}$) from the lumen into enterocytes.

Fluoroapatite

A compound formed in bones and tooth enamel when fluoride ions replace hydroxyl groups in hydroxyapatite crystals, conferring increased resistance to acid dissolution and dental caries.

Glutathione Peroxidase

A selenoenzyme containing selenium as selenocysteine that acts alongside antioxidants to reduce potentially damaging cellular peroxides to water and corresponding alcohols.