4 CLASSES OF MACROMOLECULES – HW 1-1 Carbohydrates (sugars) Lipids (fats) Nucleic Acids Proteins

How many of the classes of macromolecules do each of the following organisms have? THEY ALL CONTAIN 4 CLASSES OF MACROMOLECULES. Every organism (with the exception of viruses which may contain only proteins and nucleic acids) on the molecular level is primarily comprised of the exact same four classes of macromolecules

Molecular Similarities of Life Our realization that all living organisms share a common set of macromolecules did NOT fully develop until the mid 20th century. in the 19th century many biologists mistakenly believed that each type of organism was made up a unique set of molecules (e.g. “bird molecules” vs “dog molecules”.)

How can organisms that look so different be made up of the same types of molecules?

Molecular Similarities of Life ANS: Although the basic structural patterns of the macromolecules are the same for all organisms, there are differences in the details of structures and the number of and organization of these molecules. “ANTI-FREEZE” PROTEINS FROM DIFFERENT ORGANISMS

Why can your body only digest food that originated from other living organisms? For example, why can’t you eat a rock?, Crystal structure of a rock (fluorite)

ANS: Your body is designed to extract energy from and create cell structures from the four classes of macromolecules. It is not designed to work with radically different molecular structures. Your body does contain trace amounts of different inorganic materials, but it mainly utilizes the four macromolecules for energy and structures and movement. Structure of starch (polymer of glucose) ; glycolysis begins by digesting glucose; key metabolic pathways are extremely similar in most organisms. Crystal structure of a rock (fluorite)

Fig. 5-UN2 POLYMERS POLYMERS POLYMERS

Carbohydrates, proteins and nucleic acids can form chainlike molecules called POLYMERS. Polymers are formed by small, repeating units called monomers linked by covalent bonds HW 1-1: #2

Examples of Monomers and Polymers Carbohydrate Example HW 1-1: #3 POLYMER MONOMER Nucleic Acids Proteins Why Polymers? What is the advantage to the cell?

Resource Efficiency; Mass produce same basic building blocks with small variations HW 1-1: #4

An immense variety of polymers can be built from a small set of monomers Monomers can be connected in various combinations like the 26 letters in the alphabet can be used to create a great diversity of words. ACTS vs. CATS vs. CAST same letters, different arrangement, different meanings DIFFERENT ORDERED COMBINATIONS OF NUCLEIC ACID BASES PRODUCE….. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

An immense variety of polymers can be built from a small set of monomers DIFFERENT ORDERED SEQUENCES OF AMINO ACIDS AND HENCE DIFFERENT TYPES OF PROTEINS. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 5.2 The synthesis and breakdown of polymers (AKA CONDENSATION SYNTHESIS) Usually ∆G = +, Energy required due to entropy decrease Usually ∆G = -, Energy required due to entropy increase

Condensation synthesis examples

Hydrolysis examples