The Building Blocks of Life Section 6.4 The Building Blocks of Life

Objectives Distinguish among proteins, carbohydrates, lipids and nucleic acids. (SPI 3210.1.3) Summarize the four major families of biological macromolecules Describe the role of carbon in living organisms Compare the functions of each group of biological macromolecules. Identify positive tests for carbohydrates, lipids and proteins (SPI 3210.1.4)

New Vocabulary organic compound macromolecule polymer carbohydrate lipid protein amino acid nucleic acid nucleotide buffer

*Carbon – *Hydrogen – *Nitrogen – *Oxygen Key Elements *Carbon – *Hydrogen – *Nitrogen – *Oxygen Phosphorus – Sulfur * Most common elements in biological systems * About 95% of your body weight.

Inorganic molecules Do not contain carbon and hydrogen together. Play important roles in biological systems.

Organic molecules Carbon (skeleton) bonded to other atoms (functional groups). They determine the structure and function of living things.

Cells are 70-90% water The degree to which organic molecules interact with water affects their function.

What characteristics of an organic molecule do you think affect its interaction with water?

Polarity - Polar molecules (with +/- charges) are attracted to water molecules and are hydrophilic. - Nonpolar molecules are repelled by and do not dissolve in water and are hydrophobic. - Hydrocarbons are hydrophobic except when they have an attached ionized functional group such as carboxyl (acid) (-COOH); then the molecule is hydrophilic.

Carbon Is Unique * Four electrons in outer shell; bonds with up to four other atoms (Usually H, O, N, or other carbons). * Can bond to itself making chains and rings (back bones of organic molecules). * Characteristics allow it to form an enormous variety of organic molecules.

CARBON ATOM

Polymers Macromolecules composed of three to millions of monomer subunits.

What is a Polymers? SMALL ORGANIC MOLECULES (e.g. monosaccharides, glycerol and fatty acids, amino acids, and nucleotides) serve as monomers, the subunits of polymers.

What is a Macromolecule? The four types of large molecules comprising living things Carbohydrates (Polysaccharides) Lipids (Triglycerides)* Proteins (Polypeptides) Nucleic Acids * Not polymers

Proteins Functions Monomers Polymers Form cell structures Chemical messengers Enzymes Body defense Regulation Movement & support Monomers amino acids Polymers Polypeptides Proteins  

Carbohydrates Functions Monomers Polymers Energy Cell structures Cell recognition Used to make other molecules Monomers Monosaccharides(sugars) Polymers Poly-saccharides

Lipids Functions Components Types Energy storage Membrane Structure Chemical messengers Components Fatty acids, glycerol Types Triglycerides (Fats & Oils) Phospholipids Waxes Steroids  

Nucleic Acids Function Monomers Polymers Storage & transfer of genetic information Energy transfer Monomers Nucleotides Polymers Nucleic acids

Building a Polymer (Dehydration Synthesis) Polymers (carbohydrates, fats, proteins and nucleic acids) are built by bonding monomers together. The joining is called dehydration synthesis. (Sometimes condensation). REMOVE WATER!

Building a Polymer Chain (Remove water!)

Dehydration synthesis

Breaking Down A Polymer (Hydrolysis) Hydrolysis means to split with water. “water” (hydro–) “split” (–lysis) ADD WATER!

Breaking a Polymer Chain (Add Water!)

Hydrolysis reaction breaks down polymers Hydrolysis reaction breaks down polymers. The reverse of dehydration synthesis.

Catalyze condensation and hydrolysis of polymers. SPEED UP REACTIONS! Enzymes Catalyze condensation and hydrolysis of polymers. SPEED UP REACTIONS!

Let’s Review Compare and contrast characteristics and significance of organic vs. inorganic molecules. List the four types of polymers of biological significance List the building blocks (monomers) that form the four types of polymers of biological significance. Describe dehydration synthesis Describe hydrolysis.