A&P - Chem and energy

Comprehensive vocabulary flashcards covering atomic structure, chemical bonds, common ions, water properties, pH, biological macromolecules, and classes of energy from Chapters 2 and 3.

Atom

The smallest particle exhibiting chemical properties of an element.

Neutron

A subatomic particle located in the nucleus with no charge and a mass of $1\,\text{amu}$.

Proton

A subatomic particle located in the nucleus with a positive charge of $+1$ and a mass of $1\,\text{amu}$.

Electron

A subatomic particle with a negative charge of $-1$, located in orbitals at varying distances from the nucleus, with a mass of $\frac{1}{1800}\text{th}$ that of a proton or neutron.

Shell Model

A diagrammatic representation showing energy shells holding electrons in orbits around an atomic nucleus containing protons and neutrons.

Atomic Number

The number of protons in an atom of a given element, displayed above the chemical symbol on the periodic table.

Average Atomic Mass

The mass of both protons and neutrons in an atom, shown below the element symbol on the periodic table.

Octet Rule

The tendency of elements to lose, gain, or share electrons in order to obtain a complete outer valence shell containing $8$ electrons.

Valence Shell

The outermost electron shell of an atom, which determines its chemical reactivity and bonding capacity.

Major Elements of the Human Body

Six elements—Oxygen ($65.0\%$), Carbon ($18.0\%$), Hydrogen ($10.0\%$), Nitrogen ($3.0\%$), Calcium ($1.5\%$), and Phosphorus ($1.0\%$)—that collectively compose more than $98\%$ of human body weight.

Cation

A positively charged ion formed when an atom loses one or more electrons to reach stability.

Anion

A negatively charged ion formed when an atom gains one or more electrons to reach stability.

Polyatomic Ion

An ion composed of more than one atom carrying a charge, such as bicarbonate ($HCO_3^-$) or phosphate ($PO_4^{3-}$).

Sodium Ion ($Na^+$)

The most common extracellular cation, involved in conducting electrical signals in nerves and muscle, osmotic water movement, and plasma membrane cotransport.

Potassium Ion ($K^+$)

The most common intracellular cation, involved in electrical signaling in nerves and muscle, glycogen storage in liver and muscle, and pH balance.

Calcium Ion ($Ca^{2+}$)

A cation responsible for bone and teeth hardness, muscle contraction, exocytosis (including neurotransmitter release), blood clotting, and serving as a second messenger.

Chloride Ion ($Cl^-$)

An anion that alters nerve cell responsiveness to stimulation, serves as a component of stomach acid ($HCl$), and participates in the chloride shift in erythrocytes.

Phosphate Ion ($PO_4^{3-}$)

The most common intracellular anion that hardens bone and teeth as $Ca_3(PO_4)_2$, acts as an intracellular buffer, and forms a structural component of phospholipids, ATP, and nucleic acids ($DNA$ and $RNA$).

Ionic Bond

A chemical bond resulting from electrostatic forces binding positively charged cations and negatively charged anions together in a lattice crystal structure.

Covalent Bond

A chemical bond formed when two atoms share electrons to complete their valence shells.

Covalent Bond Types

Chemical bonds formed by sharing one pair of electrons in a single bond ($H_2$), two pairs in a double bond ($O_2$), or three pairs in a triple bond ($N_2$).

Electronegativity

The relative attraction of each atom for shared electrons in a covalent bond.

Nonpolar Covalent Bond

A covalent bond formed between two atoms of the same element or similar electronegativity that share electrons equally.

Polar Covalent Bond

A covalent bond formed between two atoms with unequal sharing of electrons due to differences in electronegativity.

Hydrogen Bond

A weak attraction formed between a partial positive hydrogen atom of one polar molecule and a partial negative atom of another polar molecule.

Cohesion

The attraction between water molecules due to hydrogen bonding.

Surface Tension

The inward pulling of cohesive forces at the surface of water, which can cause moist air sacs in the lungs to collapse unless surfactant is present.

Adhesion

The attraction between water molecules and a substance other than water.

Specific Heat

The amount of heat energy required to increase the temperature of $1\,\text{g}$ of a substance by $1^\circ\text{C}$.

Heat of Vaporization

The amount of heat required for $1\,\text{g}$ of a liquid substance to change into a gaseous phase.

Acid

A proton donor that dissociates in water to produce $H^+$ and an anion, increasing the concentration of free $H^+$ in solution.

Base

A proton acceptor that binds free $H^+$ when added to a solution, decreasing the concentration of free $H^+$ in solution.

pH Scale

A inverse measure of relative $H^+$ concentration ranging from $0$ to $14$, where values below $7$ are acidic ($H^+ > OH^-$), $7$ is neutral, and values above $7$ are basic ($H^+ < OH^-$).

Buffer

A chemical system that helps prevent pH changes by accepting excess $H^+$ from added acid or donating $H^+$ to neutralize added base.

Neutralization

The process of returning an acidic or basic solution to a neutral pH of $7$ by adding a base or acid, respectively.

Suspension

A water mixture containing material larger than $100\,\text{nm}$ that does not remain mixed unless in motion, scatters light, and appears cloudy or opaque.

Colloid

A water mixture containing protein particles ranging from $1\,\text{nm}$ to $100\,\text{nm}$ in size that remains mixed when not in motion and scatters light.

Solution

A homogeneous water mixture containing dissolved solute particles smaller than $1\,\text{nm}$ that do not scatter light or settle when standing.

Emulsion

A special category of suspension formed between water and a nonpolar liquid substance that does not mix unless shaken.

Triglycerides

The most common lipid class in living things, formed from glycerol and three fatty acids during dehydration synthesis, used for long-term energy storage, insulation, and cushioning.

Phospholipids

Amphipathic lipids composed of a polar hydrophilic glycerol/phosphate head and two nonpolar hydrophobic fatty acid tails, forming cellular membrane barriers.

Steroids

Lipids composed of four fused carbon rings (three 6-carbon rings and one 5-carbon ring) with varying side chains, including cholesterol, steroid hormones, and bile salts.

Eicosanoids

Locally signaling lipids synthesized from 20-carbon arachidonic acid that function in inflammatory responses and nervous system communication.

Monosaccharides

Simple sugar monomers, such as glucose, that serve as the basic structural units of carbohydrates.

Glycogenesis

The metabolic pathway in which excess glucose monomers are bound together and stored as glycogen in liver and muscle tissue.

Glycogenolysis

The process by which the liver hydrolyzes stored glycogen back into glucose monomers when needed by the body.

Gluconeogenesis

The metabolic process in which the liver synthesizes glucose from non-carbohydrate sources.

Nucleic Acids

Biological macromolecules composed of nucleotide monomers linked by phosphodiester bonds that store and transfer genetic information.

Deoxyribonucleic Acid (DNA)

A double-stranded nucleic acid located in nuclear chromosomes and mitochondria containing deoxyribose sugar, phosphate, and nitrogenous bases adenine, guanine, cytosine, and thymine.

Ribonucleic Acid (RNA)

A single-stranded nucleic acid located in the nucleus and cytoplasm containing ribose sugar, phosphate, and nitrogenous bases adenine, guanine, cytosine, and uracil.

Nucleic Acid Structures (DNA vs. RNA)

Structural comparison between single-stranded RNA (containing ribose and uracil) and double-stranded DNA (containing deoxyribose, thymine, and complementary hydrogen-bonded base pairs).

Adenosine Triphosphate (ATP) Structure

A nucleotide composed of an adenine base, a ribose sugar, and three phosphate groups joined by high-energy covalent bonds that release energy when broken.

Potential Energy

Stored energy or energy of position that must be converted to kinetic energy before it can do work.

Kinetic Energy

The energy of motion.

Chemical Energy

A form of potential energy stored in a molecule's chemical bonds that is released when bonds are broken during chemical reactions.

Electrical Energy

A form of kinetic energy resulting from the movement of charged particles, such as ion movement across neuronal plasma membranes.

Mechanical Energy

Kinetic energy exhibited by objects in motion due to an applied force, such as muscle contraction during walking.

Radiant Energy

Kinetic energy carried by electromagnetic waves varying in wavelength and frequency.