The Tree of Life's Macromolecules

Overview and Learning Objectives

Students start with images of living organisms, from bacteria to plants and animals. They "zoom" into cells and tissues to discover that they are made of different macromolecules. Students observe that these macromolecules are polymers. They zoom into polymers to find that some are made from almost identical monomers, while others, such as proteins, are made from a set of different monomers. They discover that all monomers making up biological macromolecules are composed of just a few types of chemical elements: C, H, O, N, P and S.

Students will be able to:

• identify typical molecular building blocks (monomers) that form biological macromolecules;
• determine the types of atoms that make up most biopolymers;
• reason about the uniformity and diversity at the atomic level of life's molecular building blocks.

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Classroom Practice

You might explain to your students that they will "zoom" into organs and tissues of plants and animals in order to discover life's essential building blocks. They will do this by looking at images and representations of the biomolecules at different magnifications. The exercise they will do includes just a few of the many possible "zooms" into the structures of living organisms. Students will view 3D models of the biomolecules, and see that many have polarized surfaces. This extends and applies the concepts of electronegativity to more complex molecules.

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Central Concepts

Key Concept:

All key components of every living cell are made of macromolecules. The four kinds of macromolecules are lipids, carbohydrates, nucleic acids, and proteins. Three of the four macromolecules are also polymers, constructed of many organic molecules called monomers that are bonded together.

Additional Related Concepts

Concept Map Available

Biology

• Membrane

Molecular Biology

• Macromolecules

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Textbook References

• Biology (Miller and Levine) Prentice Hall 5th Edition - Unit 1: Chapter 4 - The Chemical Basis of Life
• Biology (Prentice-Hall) New York Edition - Chapter Two - The Chemistry of Life
• Biology: Concepts and Connections (Pearson) 5th Ed. - Chapter 3: The Molecules of Cells
• Biology: Concepts and Connections (Pearson) 5th Edition - Chapter 2: The Chemical Basis of Life
• Biology: Exploring Life - Chapter 5: The Molecules of Life
• Biology: The Dynamics of Life - Chapter 6: The Chemistry of Life
• BSCS Blue (8th Edition) - Chapter 1: The Chemistry of Life
• Cell Biology (Pollard and Earnshaw) Saunders 2002 - Chapter Six: membrane Structure and Dynamics
• Cell Biology (Pollard and Earnshaw) Saunders 2002 - Chapter Two: Molecular Structures
• Web of Life - Chapter 2: Chemical Basis of Life

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Benchmarks and Standards

AAAS

• THE LIVING ENVIRONMENT: CELLS - A living cell is composed of a small number of chemical elements mainly carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur (Full Text of Standard)
  
  

NSES

• Life-Science: Matter, energy, and organization - 6 As matter and energy flows through different levels of organization (Full Text of Standard)
  
  

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Extensions and Connections

Advanced students might undertake the Polymerization activity, in which they investigate both addition polymerization and condensation polymerization, and then compare linear, branched, and cross-linked polymers.

http://molo.concord.org/database/activities/282.html

http://workbench.concord.org/web_content/unitIV_revised2/act1.html

This activity guide from the first activity of the three-activity module Monomers to Polymers, includes several interesting related activities for students.

The Molecular Construction Kit (http://molo.concord.org/database/activities/153.html) follows easily from this activity, and enables students to build linear and branching polymers from monomers.

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Additional Info

Additional Background

http://www.concord.org/~barbara/workbench_web/pdf/compounds.pdf

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Activity Credits

Created by CC Project: Molecular Workbench using Molecular Workbench

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Requirements

• Java 1.5+ - Java 1.5+ is available for Windows, Linux, and Mac OS X 10.4 and greater. If you are using Mac OS X 10.3, you can download MW Version 1.3 and explore within it instead.

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