Chemistry Comes Alive Flashcards

Comprehensive vocabulary flashcards covering the basics of chemistry, subatomic particles, chemical bonds, reactions, and the major organic and inorganic compounds of the human body.

Matter

The stuff of the universe that occupies space and has mass.

Energy

The capacity to do work or move matter.

Potential energy

Stored energy that has the capability to do work but is not currently doing so, such as food molecules in the stomach or water held behind a dam.

Kinetic energy

Energy in action or motion, such as the passage of food to the stomach or water flowing down a river.

Chemical energy

Energy stored in the bonds of chemical substances, such as when breaking the bonds of $ATP$ to energize a muscle cell.

Electrical energy

Energy resulting from the movement of charged particles, such as a nerve impulse traveling from the spinal cord to a muscle.

Mechanical energy

Energy directly involved in moving matter, such as kicking a ball.

Radiant energy

Energy that travels in waves, such as ultraviolet waves traveling from the sun.

Chemical element

Fundamental substances that cannot be broken down into simpler substances by ordinary chemical methods.

Major elements of the body

Oxygen, carbon, hydrogen, and nitrogen; together they make up $96.3\%$ of body mass.

Atom

The building block of an element and the smallest particle of an element that still retains its properties.

Proton

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

Neutron

A subatomic particle located in the nucleus with a neutral charge and a mass of $1\,amu$.

Electron

A subatomic particle that orbits the nucleus with a negative charge and negligible mass.

Atomic number

The number that tells how many protons are in an atom.

Mass number

The sum of the protons and neutrons in an atom's nucleus.

Isotope

Structural variations of an element that have the same number of protons but differ in the number of neutrons.

Radioisotope

An unstable atom that decomposes over time into a more stable form, such as tritium ($^{3}H$).

Molecule

A particle formed by two or more atoms bound together.

Compound

A substance formed when two or more different kinds of atoms bind, such as $H_2O$, $CH_4$, or $CO_2$.

Mixture

Substances composed of two or more components physically intermixed without chemical bonding.

Solution

A homogeneous mixture where solute particles are very tiny, do not settle out, and do not scatter light, such as table salt ($NaCl$) in water.

Colloid

A heterogeneous mixture where solute particles scatter light but do not settle out, such as cytosol.

Suspension

A heterogeneous mixture where solute particles are very large, settle out, and may scatter light, such as sand in water.

Valence shell

The outermost electron shell of an atom that determines its chemical reactivity.

Octet rule

The rule of eights; the tendency of atoms to interact in such a way that they have eight electrons in their valence shell.

Ionic bond

A chemical bond formed by the attraction between two oppositely charged ions, such as in sodium chloride.

Covalent bond

A chemical bond formed by the sharing of pairs of electrons between atoms.

Hydrogen bond

A weak attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom with a slightly negative charge.

Synthesis reaction

A chemical reaction where atoms or molecules combine to form a larger, more complex molecule ($A + B \rightarrow AB$).

Decomposition reaction

A chemical reaction where a molecule is broken down into smaller constituent parts ($AB \rightarrow A + B$).

Exchange reaction

A chemical reaction involving both synthesis and decomposition where parts of reactant molecules change partners ($AB + CD \rightarrow AD + CB$).

Exergonic reaction

A reaction that releases energy, resulting in products with less potential energy than the reactants.

Endergonic reaction

A reaction that absorbs energy, resulting in products that contain more potential energy than the reactants.

Enzymes

Biological catalysts, usually proteins, that increase the rate of chemical reactions by lowering activation energy.

Electrolytes

Substances such as salts, acids, and bases that conduct electrical current in solution.

Acid

A substance that releases hydrogen ions ($H^+$) in detectable amounts; also known as a proton donor.

Base

A substance that takes up hydrogen ions ($H^+$) or releases hydroxyl ions; also known as a proton acceptor.

Buffer

A chemical system, such as the bicarbonate system, that resists changes in blood $pH$.

Dehydration synthesis

The process by which organic molecules are joined together, resulting in the release of a water molecule.

Hydrolysis

The process by which organic molecules are broken down through the addition of a water molecule.

Glucose

The specific carbohydrate monomer ($C_6H_{12}O_6$) referred to as "blood sugar."

Glycogen

The storage carbohydrate (polysaccharide) found in animal cells.

Triglycerides

Lipids composed of three fatty acids and one glycerol; known as fats when solid and oils when liquid.

Phospholipid

A modified triglyceride that is a key component of cell membranes, containing both polar and nonpolar regions.

Amino acids

The building blocks of proteins.

Peptide bond

The covalent bond that joins amino acids together.

Protein denaturation

The loss of a protein's specific three-dimensional shape, often caused by changes in temperature or $pH$.

Nucleotides

The building blocks of nucleic acids, consisting of a nitrogen-containing base, a pentose sugar, and a phosphate group.

ATP (Adenosine triphosphate)

The primary energy-transferring molecule in cells that provides a form of energy that is immediately usable by all body cells.