Chapter 1-8: Introduction to Chemistry and Cellular Biology (Video)

Vocabulary flashcards covering energy types, atomic structure, chemical bonds, isotopes, hydrophilic/hydrophobic interactions, hydrogen bonds, antioxidants, and metabolism.

Kinetic energy (mechanical energy)

Energy of motion; directly involved in moving matter (e.g., muscle contraction, heartbeats).

Electrical energy

Energy carried by moving electrons; used to measure electrical activity (ECG, brain waves).

Radiant energy

Energy from the sun; important as a source of energy in biology but not a primary internal energy store.

Chemical energy

Energy stored in chemical bonds; transferred to ATP to power cellular processes.

Gravitational energy

Potential energy due to position in a gravitational field.

ATP (adenosine triphosphate)

Primary energy currency of the cell; produced via cellular respiration; powers work.

Cellular respiration

Process that converts glucose and oxygen into ATP, CO2, and H2O.

CHNOPS

The six most common elements in living organisms: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.

Atomic number

Number of protons in the nucleus; equals the number of electrons in a neutral atom; identifies the element.

Mass number

Total number of protons and neutrons in the nucleus; determines atomic mass and can vary with isotopes.

Nucleus (atom)

Central region of the atom containing protons and neutrons; houses most of the atom’s mass.

Proton

Positively charged subatomic particle in the nucleus.

Neutron

Electrically neutral subatomic particle in the nucleus.

Electron

Negatively charged subatomic particle orbiting the nucleus; very small mass; involved in bonding.

Electron shells (orbitals)

Regions around the nucleus where electrons reside; first shell holds up to 2, second up to 8, etc.

Octet rule

Outer electron shells prefer to have eight electrons to be stable (except hydrogen’s first shell).

Valence shell

Outermost electron shell; electrons here determine chemical reactivity.

Valence electrons

Electrons in the valence shell that determine how an atom bonds and reacts.

Cation

Ion with a positive charge formed when an atom loses electrons.

Anion

Ion with a negative charge formed when an atom gains electrons.

Ionic bond

Bond formed by transfer of electrons; results in a cation and anion (e.g., NaCl).

Sodium chloride (NaCl)

Table salt; formed by ionic bonding; essential for nerve signaling.

Covalent bond

Bond formed by sharing electrons; can be polar or nonpolar; forms molecules.

Polar covalent bond

Unequal sharing of electrons creating partial charges; common in water molecules.

Nonpolar covalent bond

Even sharing of electrons; little or no partial charges (e.g., O2).

Molecule

Two or more atoms bonded together; can be same or different elements.

Compound

Molecule composed of two or more different elements.

Molecular formula

Notation showing the types and numbers of atoms in a molecule (e.g., C6H12O6 in glucose).

Water (H2O)

Molecule with covalent bonds; polar; exhibits partial charges; key solvent in biology.

Hydrogen bond

Weak bond between partial positive hydrogen and a more electronegative atom (often O or N); important in water, DNA, and proteins.

Hydrophilic

Water-loving; polar or charged molecules that dissolve in water.

Hydrophobic

Water-fearing; nonpolar molecules that do not dissolve in water.

Free radical

Atom or molecule with an unpaired electron; highly reactive and can damage cells.

Antioxidant

Molecules that neutralize free radicals by donating electrons (e.g., selenium, zinc, beta carotene, vitamins).

Isotope

Atom of an element with a different number of neutrons; same protons, different mass number.

Radioisotope

Unstable isotope that emits radiation; used in diagnostics and therapy (e.g., iodine-131, iodine-123).

Iodine-131

Radioisotope used in thyroid imaging and treatment; contrasts normal vs Graves’ disease.

Hydrogen bond (revisited)

Weak attraction between a partially positive hydrogen and an electronegative atom; essential in biological macromolecules.

Noble gases

Elements with filled valence shells; generally inert (e.g., helium).

Homeostasis

Maintenance of a stable internal environment through coordinated physiological processes.

Anabolic reaction (synthesis)

Chemical reactions that build larger, more complex molecules; energy requiring.

Catabolic reaction (decomposition)

Chemical reactions that break down molecules into simpler ones; energy released.

Metabolism

All chemical reactions in the body, including anabolic and catabolic processes.