Biology 120 Notes (Part 4) Starting the Discussion on Macromolecules

Macromolecules

• ==Macromolecules== are large molecules made of smaller molecules joined together.
• the four classes of macromolecules are: carbohydrates, lipids, proteins, and nucleic acids.
• Monomers are the building blocks of polymers.
• ==Monomers== are subunits.
• The monomers of carbohydrates are ==monosaccharides,== and its polymers are ==polysaccharides.==
• The monomers of lipids are ==glycerol and fatty acids==, and its polymers are ==fats.==
• The monomers of proteins are ==amino acids==, and its polymers are ==polypeptides.==
• The monomers of nucleic acids are ==nucleotides==, and its polymers are ==DNA and RNA.==

Hydrolysis and Dehydration Reactions

• ==Dehydration (synthesis) reactions== joins monomers together by a covalent bond and water is released.
• ==Hydrolysis (degradation) reactions== take place when water molecules are added to break a covalent bond.
• (“Hydro” means water and “lysis” means breaking/rupturing.)

Synthesis and Degradation

• ==Enzymes== are required for cells to carry out reactions.
• Enzymes are a molecule that speed up a chemical reaction.
• They are not consumed or changed in the reaction.

Carbohydrates

• ==Carbohydrates== are found in grains, fruits, and veggies.
• They provide energy to the body in the form of glucose, and they provide cell structure.
• The three main types of carbohydrates are: ==monosaccharides (one), disaccharides (two), and polysaccharides (many).==
• Carbohydrates have the molecular formula CH20.
• There are two hydrogens for each single carbon and oxygen.
• Carbohydrates contain a carbonyl group (C=O), hydroxyl groups (O-H), and many carbon-hydrogen bonds (C-H).
• Carbohydrates are hydrophilic (they love water).

What Distinguishes One Monosaccharide from Another?

• Monosaccharide monomers are simple sugars that structurally vary in four primary ways.
• The first way that they structurally vary is in the number of carbons present. If there are three carbons present, it would be known as a ==“triose,”== if there are five carbons present, then it would be a ==“pentose,”== if there are six carbons, then it would be a ==“hexose.”==
• The second way they vary is the arrangement of functional groups.
• The third way they vary is by linear and alternate ring forms.

Three Structural Isomers of a Hexose Monosaccharide

• The structural isomers/formula is: C6H12O6.

1. ==Glucose== is an important source of energy.
2. ==Galactose== is part of lactose/milk sugar.
3. ==Fructose== is part of sucrose/fruit.

\