Module 5 The Chemistry of Life


Anything that has mass and takes up space


explanation or representation of something that cannot be seen


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


Chemicals that result from atoms linking together

physical change

A change that affects the appearance but not the chemical makeup of a substance.

chemical change

A change that alters the makeup of the elements or molecules of a substance.


One of the three forms--solid, liquid, or gas--which every substance is capable of attaining.


The random motion of molecules from an area of high concentration to an area of low concentration.


A measurement of how much solute exists within a certain volume of solvent

semipermeable membrane

A membrane that allows some molecules to pass through but does not allow other molecules to pass through.


The tendency of a solvent to travel across a semipermeable membrane into areas of higher solute concentration.


A substance that alters the speed of a chemical reaction but is not used up in the process.

organic molecules

A molecule that contains only carbon and any of the following: hydrogen, oxygen, nitrogen, sulfur, and/or phosphorous.


Two different molecules that have the same chemical formula


Simple carbohydrates that contain 3 to 10 carbon atoms.


Carbohydrates that are made up of two or more monosaccharides


Carbohydrates that are made up of more than two monosaccharides

dehydration reaction

A chemical reaction in which molecules combine by removing water


Breaking down complex molecules by the chemical addition of water


Lacking any affinity to water.

saturated fats

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

unsaturated fats

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

peptide bond

Bonds that connect amino acids.

hydrogen bond

A strong attraction between hydrogen atoms and certain other atoms (usually oxygen or nitrogen) in specific molecules.


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