Chemistry of Life

Comprehensive vocabulary flashcards covering the chemical foundations of life, including atomic structure, chemical bonding, reactions, and major organic and inorganic compounds.

Matter

Anything that occupies space and has mass (weight).

Energy

The ability to do work.

Elements

Fundamental units of matter; approximately $96 \%$ of the body is made from four specific types: Carbon (C), Oxygen (O), Hydrogen (H), and Nitrogen (N).

Atoms

The building blocks of elements.

Nucleus

The central part of an atom containing Protons ($p^+$) and Neutrons ($n^0$).

Electrons ($e^-$)

Atomic subparticles found outside of the nucleus.

Atomic number

A value equal to the number of protons that the atoms contain.

Atomic mass number

The sum of the protons and neutrons in an atom.

Isotopes

Atoms that have the same number of protons but vary in the number of neutrons.

Atomic Weight

A value close to the mass number of the most abundant isotopes which reflects natural isotope variation.

Radioactivity

The process of spontaneous atomic decay.

Radioisotope

A heavy isotope that tends to be unstable and decomposes to a more stable isotope.

Molecule

Two or more like atoms combined chemically.

Compound

Two or more different atoms combined chemically.

Electron shells

Energy levels occupied by electrons; shells closest to the nucleus fill first and are most strongly attracted.

Valence shell

The outer electron shell that involves interactions for bonding.

Rule of 8s

A shell stability rule where Shell 1 has $2$ electrons, Shell 2 has $8$ ($10$ total), and Shell 3 has $8$ ($18$ total).

Inert Elements

Stable elements that have complete valence shells and do not form bonds.

Reactive Elements

Unstable elements with valence shells that are not full, leading them to gain, lose, or share electrons.

Ionic Bonds

Bonds formed when electrons are completely transferred from one atom to another, resulting in charged particles called ions.

Anions

Negatively charged ions.

Cations

Positively charged ions.

Covalent Bonds

Bonds in which atoms become stable through shared electrons; can be single (one electron shared) or double (two electrons shared).

Non-polar molecules

Covalently bonded molecules that are electrically neutral.

Polar molecules

Molecules that have a distinct positive and negative side.

Hydrogen bonds

Weak chemical bonds where hydrogen is attracted to the negative portion of a polar molecule, providing attraction between molecules.

Synthesis reaction

A reaction where atoms or molecules combine ($A+B \rightarrow AB$) and energy is absorbed for bond formation.

Decomposition reaction

A reaction where a molecule is broken down ($AB \rightarrow A+B$) and chemical energy is released.

Exchange reaction

A reaction involving both synthesis and decomposition where parts of molecules are switched ($AB + C \rightarrow AC + B$).

Organic compounds

Covalently bonded compounds that contain carbon, such as glucose ($C_6H_{12}O_6$).

Inorganic compounds

Simpler compounds that lack carbon, such as water ($H_2O$).

Water

The most abundant inorganic compound, vital for its high heat capacity, solvent properties, chemical reactivity, and cushioning.

Salts

Inorganic compounds that easily dissociate into ions in water and include electrolytes that conduct electrical currents.

Acids

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

Bases

Proton acceptors.

Neutralization reaction

A reaction in which acids and bases react to form water and a salt.

pH

A measure of the relative concentration of hydrogen ions; $7$ is neutral, below $7$ is acidic, and above $7$ is basic.

Buffers

Chemicals that can regulate pH change.

Carbohydrates

Organic compounds containing carbon, hydrogen, and oxygen, including sugars and starches.

Monosaccharides

Simple sugars.

Disaccharides

Two simple sugars joined together by dehydration synthesis.

Polysaccharides

Long branching chains of linked simple sugars, such as starch.

Lipids

Organic compounds containing C, H, and O that are insoluble in water; C and H outnumber O.

Neutral fats (triglycerides)

Lipids composed of fatty acids and glycerol that serve as a source of stored energy.

Phospholipids

Lipids characterized by a polar 'head' and nonpolar 'tail' that form cell membranes.

Steroids

A category of lipids that include cholesterol, bile salts, vitamin D, and some hormones.

Proteins

Compounds made of amino acids containing carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur.

Enzymes

Proteins that act as biological catalysts to increase the rate of chemical reactions.

Nucleic Acids

Molecules that provide the blueprint of life, including DNA and RNA; built from nucleotide bases (A, G, C, T, U).

Deoxyribonucleic acid (DNA)

A double helix molecule that replicates before cell division and providing instructions for every protein in the body.

Adenosine triphosphate (ATP)

The chemical energy used by all cells; energy is released by breaking high energy phosphate bonds.