Chapter 3: Macromolecules

Got Lactose?

– Many people in the world suffer from lactose intolerance Lacking an enzyme that digests lactose, a sugar found in milk

Lactase is secreted in small intestinal track Lactose intolerance is mostly affected by age and heritage. Most babies are able to digest lactose. This ability declines after 2yrs 75% of African Americans and Native Americans and 90% of Asian Americans are lactase deficient

What’s the norm..? The ability to break down lactase as you get older is actually the mutation. 9000yrs ago consumption of milk products increased This large difference in population has become a problem in food industry

Until…..

What level of study? Molecular Level

Review: Hydrocarbons Organic- made of a carboskeleton Contain only Hydrogen and Carbon Can have single or double bonds

Isomers Same formula, different structure This changes the chemical properties!

4 Types of Macromolecules Carbohydrates Lipids Proteins Nucleic Acids

3.3 Cells make a huge number of large molecules from a small set of small molecules The four classes of biological molecules contain very large molecules –They are often called macromolecules because of their large size –They are also called polymers because they are made from identical building blocks strung together –The building blocks are called monomers

Monomers and Polymers Monomers: the smaller subunits that serve as the building blocks of a polymer Polymers: the long molecules consisting of many similar or identical building blocks

Dehydration and Hydrolysis Dehydration synthesis – removal of water to form polymers Hydrolysis – addition of water to break up a polymer

Unlinked monomer Short polymer

Unlinked monomer Short polymer Longer polymer Dehydration reaction

Hydrolysis