Chemistry of Organic Molecules

Chapter 3 Mader Biology

Organic Molecules

Four Classes• Carbohydrates• Lipids• Proteins • Nucleic Acids

Organic Molecules

Organic molecules contain a carbon backbone with various functional groups attached

The functional groups have various properties

that make the molecule behave a

certain way in solution

Pop Quiz… (Just for Fun!)

• How well do you know your functional groups?

Macromolecules

• Carbohydrates, lipids, proteins, and nucleic acids are all macromolecules

• Macromolecules are made from linking monomers into polymers through dehydration synthesis

Enzymes make it Happen

What is that!

Carbohydrates

• Universally used as immediate energy, to make ATP during cellular respiration, but also play a structural role

Broken Down for Energy Cellulose, structure in plants and the most abundant molecule on Earth

Dehydration synthesis/Hydrolysis

Simple sugar

Disaccharide

Polysaccharide

Carbohydrates• Alpha linkage can easily be broken down by humans and

other animals but Beta linkage can only be broken down by certain bacteria

Alpha linkage

Beta linkage

Lipids

• A variety of organic molecules are classified as lipids

• Insoluble in water• Fats, a type of lipid in animals, and oils, a type

of lipid in plants, are used for energy storage• Phospholipids make up the bi-layers of

membranes

Fats and Oils

• Made from the subunit molecules Glycerol and fatty acids

• Known as a triglyceride

Phospholipids

• Made from the subunit molecules phosphate, glycerol, and fatty acids

• Compose the bulk of a cell membrane

Steroids• Composed of four fused carbon rings with various functional groups giving it

different properties• Cholesterol freely floats around in the blood as a waxy substance• It is a precursor to the sex hormones testosterone and estrogen• It is integrated into all cell membranes as a lubricant• Cholesterol can be classified as LDL, “Bad Cholesterol”, and HDL “Good Cholesterol”

He must have good genes

Waxes• Fatty acid bound to a long chain alcohol• Protect plants and animals

Proteins

• Approximately 50% of the dry weight of a cell consists of protein

• What are some of their functions in a cell? Functions:•Support•Enzymes•Transport•Defense•Hormones•Motion

Proteins… How are they made?

• Through transcription and translation which links the correct amino acids together in the correct sequence

Amino Acids… Building Blocks of Proteins

Protein Shape

Proteins can have up to four levels of structure1. Primary-Order of A.A.2. Secondary-Hydrogen

bonding between A.A.3. Tertiary-Covalent

bonding between R Groups

4. Quaternary-Two or more polypeptides join