Summary of Chapter 5.1

Vocabulary:
organic molecule: carbon based molecule
inorganic molecule: non carbon based molecule
hydrocarbon: organic molecules that are composed of only carbon and hydrogen
functional group: a group of atoms within a molecule that interacts in predictable ways with other molecules
hydrophilic: attracting water molecules
monomer: small molecular unit that is the building block of a larger molecule
polymer: long chain of small molecular units (monomers)

Carbon is the main ingredient of organic molecules. They may form bonds with other carbon atoms to make an endless variety of carbon skeletons. Organic molecules are important, such as hydrocarbon. Hydroxyl groups are hydrophilic so they often are surrounded by water molecules in an aqueous environment. Large molecules are built by monomers. Cells connect monomers into polymers and every living cell has thousands of polymers. When a monomer is added to a polymer, a water molecule releases, resulting into a dehydration reaction. . Polymers can also be broken down to receive their energy. Cells break bonds between monomers by adding water to them. A hydrolysis reaction is when water is used to break down the polymer. Water is removed to build a polymer, and water is added to break it down.

Concept Check
1. Draw a molecule that has a three-carbon skeleton and a hydroxyl group on the middle carbon. (Hint: The molecule's formula is C3H80)
2. Explain the connections between monomers and polymers. Monomers are small molecular units that link together into long chains called polymers.
3. What molecule is released during the construction of a polymer? What is this reaction called? Each time a monomer is added to a chain, a water molecule is released. This reaction is called a dehydration reaction.
4. Draw at least three ways in which five carbon atoms could be joined to make different carbon skeletons.