Chapter 02: Chemical Basis of Life

Vocabulary flashcards generated from Chapter 02 lecture notes covering fundamental chemistry, atomic structures, chemical bonds, reactions, pH, and organic cellular constituents.

Matter

Anything that takes up space and has mass; composed of elements.

Mass

The amount of matter present in an object.

Weight

The heaviness of an object due to the gravitational pull on its mass.

Chemistry

The branch of science that studies the composition, properties, and interactions of matter.

Biochemistry

Biological chemistry, which studies physiological processes and disease.

Elements

Simplest types of matter with certain chemical properties, of which 92 occur naturally.

Compounds

Chemical combinations of different elements.

Atoms

The smallest particles of an element that retain the properties of that element.

Bulk Elements

Elements required by the body in large amounts, including $C$, $O$, $H$, $N$, $S$, and $P$.

Trace Elements

Elements required by the body in small amounts, such as $Fe$ and $I$.

Ultratrace Elements

Elements required by the body in very minute amounts, such as $As$.

Proton

Relatively large subatomic particle that carries a single positive electrical charge and is found within an atomic nucleus.

Neutron

Relatively large subatomic particle about the same weight as a proton; it is uncharged (electrically neutral) and found within an atomic nucleus.

Electron

Extremely small subatomic particle with almost no weight that carries a single negative electrical charge and is in constant motion around an atomic nucleus.

Atomic Number

The number of protons in the nucleus of an atom of a specific element.

Mass Number

The total number of protons plus neutrons in one atom.

Isotopes

Atoms with the same atomic number but different mass numbers due to having different numbers of neutrons.

Ionizing Radiation

Radiation (alpha, beta, and gamma) with energy capable of removing electrons from atoms, resulting in the formation of damaging free radicals or ions.

Molecule

A particle formed when two or more atoms chemically combine.

Compound Particle

A particle formed when two or more atoms of different elements chemically combine.

Ion

An electrically charged particle formed from an atom that has gained or lost one or more electrons.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Ionic Bonds

Strong chemical bonds formed when ions of opposite electrical charges attract.

Covalent Bonds

Strong chemical bonds formed between atoms that share pairs of electrons.

Nonpolar Covalent Bonds

Covalent bonds in which electrons are shared equally between atoms with the same electronegativity.

Polar Covalent Bonds

Covalent bonds in which electrons are not shared equally due to differences in atomic electronegativity, forming polar molecules with unequal charge distribution.

Hydrogen Bonds

Relatively weak attractions between a slightly positive hydrogen end of one polar molecule and a slightly negative nitrogen or oxygen end of a nearby polar molecule.

Reactants

The starting materials of a chemical reaction, which can be atoms, ions, or molecules.

Products

The substances formed at the end of a chemical reaction.

Synthesis Reaction

A chemical reaction where a more complex chemical structure is formed from simpler starting materials.

Decomposition Reaction

A chemical reaction in which chemical bonds are broken to form a simpler chemical structure.

Exchange Reaction

A chemical reaction in which chemical bonds are broken and new bonds are formed to trade components.

Reversible Reaction

A chemical reaction where the formed products can react to change back into the original reactants.

Electrolytes

Substances that release ions in water, producing a solution capable of conducting an electric current.

Acids

Electrolytes that dissociate in water to release hydrogen ions ($H^+$).

Bases

Substances that release ions that can combine with hydrogen ions ($H^+$).

Salts

Electrolytes formed by the reaction between an acid and a base.

pH Scale

A scale running from 0 through 14 that indicates the hydrogen ion concentration in a solution.

Acidemia

A condition occurring when blood pH drops to between 7.0 and 7.3.

Alkalemia

A condition occurring when blood pH rises to between 7.5 and 7.8.

Buffers

Chemicals that act to resist changes in pH by binding and releasing ions.

Organic Molecules

Molecules containing carbon ($C$) and hydrogen ($H$) that dissolve in water or organic liquids and do not release ions if water-soluble.

Inorganic Molecules

Molecules that generally do not contain both carbon ($C$) and hydrogen ($H$), usually dissolve in water, and dissociate into ions.

Monosaccharides

Single sugar carbohydrates, such as glucose and fructose.

Disaccharides

Double sugar carbohydrates, such as sucrose and lactose.

Polysaccharides

Complex carbohydrates formed from chains of multiple monosaccharides, such as starch, glycogen, and cellulose.

Triglycerides

The most abundant lipids in the body, used for cellular energy and composed of 1 molecule of glycerol and 3 fatty acids.

Phospholipids

Molecules containing 1 glycerol, 2 fatty acids, and a phosphate group, serving as the main structural component of cell membranes.

Saturated Fatty Acids

Fatty acids containing only single carbon-carbon bonds, typically solid at room temperature and primarily of animal origin.

Unsaturated Fatty Acids

Fatty acids containing one or more carbon-carbon double bonds, typically liquid at room temperature and primarily of plant origin.

Steroids

Lipids containing 4 connected rings of carbon, such as cholesterol, used as cell membrane components and hormone precursors.

Proteins

Organic compounds composed of amino acids linked by peptide bonds, used for structures, energy, hormones, enzymes, and antibodies.

Peptide Bonds

Chemical bonds formed between the amino group of one amino acid and the carboxyl group of an adjacent amino acid.

Denaturation

A change in the secondary and tertiary structure of a protein caused by factors like heat, radiation, chemicals, or pH changes, rendering enzymes nonfunctional.

Nucleic Acids

Organic macromolecules composed of nucleotides that store genetic code ($DNA$) or assist in protein synthesis ($RNA$).

Nucleotides

Building blocks of nucleic acids, each consisting of a sugar, a phosphate group, and an organic base.

Computerized Tomography (CT) Imaging

A diagnostic technique using an X-ray emitting device to produce three-dimensional images of soft tissues.

Positron Emission Tomography (PET) Imaging

A diagnostic technique using positron-emitting radioactive isotopes to visualize active biochemical processes and blood flow.