Biochemistry – Carbohydrates and Proteins Contemporary Biology Monkemeier

Four Classes of Macromolecules Carbohydrates (Sugars) Proteins Lipids (Fats) Nucleic Acids All are put together using dehydration synthesis and broken down using hydrolysis.

Carbohydrates (sugars) Carbohydrates contain Carbon (C), Hydrogen (H), and Oxygen (O) in a special ratio of 1:2:1. The smallest carbohydrates are known as Monosaccharides. Monosaccharides are the subunits (monomers) that get linked together to build larger carbohydrates (polymers)

Carbohydrates – The Monosaccharides The smallest carbohydrates are called monosaccharides. Monosaccharides contain chemical energy that organisms use as a source of quick energy. Examples of Monosaccharides are Glucose, Galactose and Fructose.

Monosaccharides

Disaccharides Disaccharides are carbohydrates composed of TWO monosaccharides. Disaccharides include: Sucrose, Lactose and Maltose. Sucrose is table sugar and lactose is found in milk and dairy products. People who are lactose intolerant have trouble breaking the bond between the two monosaccharides.

Building Disaccharides! Dehydration Synthesis (aka Condensation) is used to link two monosaccharides together.

Polysaccharides Polysaccharides are composed of many monosaccharides linked together. Examples of polysaccharides include starch, glycogen, cellulose and chitin. Each polysaccharide has its own function (job). Polysaccharides are built using dehydration synthesis (aka condensation)

Four Important Polysaccharides Starch = Plants store glucose as starch Glycogen = Fungi and animals store glucose as glycogen Cellulose = Composes plant cell walls Chitin = composes the exoskeleton of arthropods (insects, lobsters, crabs, etc.)

Polysaccharides

Starch vs. Cellulose

Proteins Proteins have many roles in organisms. Proteins are molecules for structure and support can be enzymes which are biological catalysts can act as transport molecules are part of structures that help organisms move

Proteins Are made of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). The subunits (monomers) of proteins are amino acids. Amino acids are linked together by covalent bonds known as peptide bonds when proteins are made.

Proteins Proteins are built by using the chemical reaction known as dehydration synthesis. Amino acids are linked together to build proteins. Amino acids are the monomers (subunits) of proteins.

Amino Acids = Monomers of Proteins! There are 20 different amino acids that can be used to build a protein. Each amino acid has the same basic structure:

Building Proteins= Forming Peptide bonds between amino acids!

Enzymes = Special Proteins Enzymes are proteins that act as biological catalysts. Catalysts speed up chemical reactions by lowering the amount of energy it takes for the reaction to start (aka activation energy) Each Enzyme has a specific substance (substrate) that it acts upon.

Enzymes and Substrates Each enzyme recognizes its substrate by its shape. The enzyme and substrate fit together like a “lock and key”. If the shape of the enzyme is changed it will not fit or recognize its substrate and it will not be able to catalyze the chemical reaction.

Enzymes and Substrates!

Enzymes and Activation Energy!

Enzymes and Chemical Reactions Remember that Enzymes speed up chemical reactions by lowering the activation energy. Each enzyme is specific for its substrate due to its shape. If the shape of the enzyme is affected, the enzyme will not speed up the chemical reaction.

Endothermic or Exothermic? Endergonic or Exergonic?

Endothermic or Exothermic? Endergonic or Exergonic?

Quiz tomorrow relating to Carbohydrates and Proteins.