The Chemistry of Life

Vocabulary flashcards based on key terms and concepts from the lecture notes on the chemistry of life.

Atomic number

The number of protons in an atom, unique to each type of atom.

Element

A collection of atoms that all have the same number of protons.

Periodic table

A table of the chemical elements arranged in order of atomic number.

Isotope

One of several forms of an element, each containing the same number of protons but a different number of neutrons.

Atomic mass

The sum of the protons and neutrons in an atom.

Compound

Chemicals that result when two or more atoms join together chemically.

Molecule

A molecule that contains atoms of at least two different elements.

Ionic bond

A chemical bond formed when one or more electrons are transferred from one atom to another.

Ion

Positively or negatively charged atoms resulting from the transfer of electrons.

Covalent bond

Chemical bond formed by the sharing of electrons between two or more atoms.

Polar molecule

A molecule in which there is an unequal distribution of the negatively charged electrons causing a partial positive charge at one end and a partial negative charge at the other.

Hydrogen bonds

A weak electrical attraction between a partially positive hydrogen atom and a partially negative atom of another molecule.

Solvent

A substance in which other substances are dissolved; for example, water.

Solute

A dissolved substance.

Solution

A mixture of solutes dissolved in a solvent.

Aqueous solution

A solution in which water is the solvent.

Cohesion

An attractive force that holds molecules of the same substance together.

Adhesion

An attractive force that holds molecules of different substances together.

Heat capacity

The amount of heat energy required to increase the temperature of a substance.

Organic molecules

Molecules found in living organisms that contain carbon in rings or long chains, attached to other atoms like hydrogen, oxygen, nitrogen, sulfur, and/or phosphorus.

Biosynthesis

The process by which living organisms produce larger molecules from smaller ones.

Isomers

Two different molecules that have the same chemical formula.

Monosaccharides

The building blocks of more complex carbohydrates, also called simple sugars.

Disaccharides

Carbohydrates that are made up of two monosaccharides.

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides.

Dehydration reaction

A chemical reaction in which molecules combine by removing water.

Starch

A polysaccharide consisting of many glucose molecules stored in plants.

Glycogen

A polysaccharide consisting of many glucose molecules stored in animals.

Cellulose

A polysaccharide consisting of many glucose molecules found in the cell wall of plants.

Hydrolysis

Breaking down complex molecules by the chemical addition of water.

Hydrophobic

Lacking any affinity to water, from the Latin meaning 'water-fearing'.

Saturated fat

A lipid made from fatty acids that have no double bonds between their carbon atoms.

Unsaturated fat

A lipid made from fatty acids that have at least one double bond between their carbon atoms.

Amino acids

The building blocks of proteins, each containing a carboxyl group and an amino group.

Hydrophilic

Attracts water molecules.

Peptide bond

A bond that links amino acids together in a protein.

Activation energy

The energy needed to get reactions started.

Active site

Area of an enzyme to which a specific substrate fits.

Substrate

A specific reactant acted on by an enzyme.

Denaturation

The process in which the normal shape of a protein is lost, usually due to heat.

Nucleotides

The building blocks of DNA and RNA.

Protons

Positively charged particles in an atom.

Electrons

Negatively charged particles in an atom.

Neutrons

Particles with no charge in an atom.

Lock and key theory

The theory stating that an enzyme has an active site that is specifically shaped for its target molecule.

Nucleotide bases

The sequence of nucleotide bases in DNA that stores information.

Hydrogen bonds in DNA

Bonds that hold the two helixes of DNA together.

Proteins' shape

Determined by the order of amino acids; shape is crucial for function.