Macromolecules of Life

Organic v. Inorganic Organic molecules are carbon based; they are the second most common molecules found in living things next to water. Inorganic molecules are not carbon based. (exceptions: CO 2 ). Organic molecules can fall into four groups of macromolecules  Carbohydrates  Lipids  Proteins  Nucleic Acids They are each composed of multiple monomers, single units, that are bonded together to form polymers, many units bonded together.

Condensation/Dehydration Reaction – Producing a Polymer When two monomers come together to make a polymer they undergo a condensation/ dehydration reaction. The two join to make one molecule and end up. producing a water

Hydrolysis – Breaking a Polymer into Monomers When a polymer is broken down into its monomers it undergoes a hydrolysis reaction. Here water is added to break apart a polymer.

Polar and Nonpolar Molecules Nonpolar molecules have an evenly distributed charge. They are called hydrophobic or water fearing. Polar molecules have an uneven distribution of charge. They are hydrophilic or water loving. Most macromolecules of life start as hydrocarbons, molecules composed of C and H. Hydrocarbons are nonpolar which creates an issue since our bodies are predominantly made of water. Therefore, a functional group is added to change the various characteristics of a molecule to make it polar.

Functional Groups

Carbohydrates Elements: C, H, O – distinguishing fact, always occur C,H 2,O Monomer: monosaccharides; C 6 H 12 O 6 isomers

Carbohydrates 2 monosaccharides make a disaccharide More than 2 monosaccharides make a polysaccharide Examples and functions:  (M) Glucose – source of energy for the body  (D) Sucrose – quick source of energy  (P) Glycogen – stored energy, many linked glucoses  (P) Cellulose – component of the cell wall  (P) Chitin – Exoskeleton of insects and crustaceans

Lipids Elements: C, H, O – distinguishing feature is that they have large amounts of C and H but little O. They are nonpolar and insoluble. Monomers: fatty acids and glycerols

Lipids Examples and functions of each type  FA - 2 types: Saturated and Unsaturated. Saturated have as many hydrogens bonded to the central carbons as possible. Unsaturated do not have as many hydrogens as possible because carbon made a double bond. Saturated are extremely unhealthy for humans because they can clog arteries.  Phospholipids are important because they build the cell membrane of every kind of cell.  Triglycerides are fats – found in human blood and can contribute to heart disease  Steroids are not all bad. Some examples are cholesterol, estrogen and testosterone

Proteins Elements: C, H, O, N, and S – distinguishing element is S Monomer: amino acid; there are 20. Components of an amino acid: Two amino acids are joined by a peptide bond

Proteins The order, number, and types of amino acids are what makes different proteins. Examples: Proteins have different functions  Hemoglobin – carries oxygen on the red blood cells.  Insulin – regulates blood sugar  Enzymes ~ Enzymes typically end with -ase; lactase, sucrase, polymerase; speed up chemical reactions

Proteins There are 4 levels to the structure of a protein  Primary – combination of amino acids  Secondary – structure that the amino acids build – sheets and helixes  Tertiary – globular (3-D) shape that they take  Quaternary – when 2 or more join together

Nucleic Acids Elements: C, O, H, P, N – distinguishing element is P Monomer: nucleotides. It is composed of a 5 C sugar, a Phosphate group, and a nitrogenous base

Nucleic Acids DNA (Deoxyribonucleic Acid) – genetic information; has deoxyribose as its sugar RNA (Ribonucleic Acid) – a copy of the genetic information that makes proteins; has ribose as its sugar. Five Nitrogenous bases:  Adenine (both DNA and RNA)  Thymine (only DNA)  Guanine (both DNA and RNA)  Cytosine (both DNA and RNA)  Uracil (only RNA)