Science ObjectDigital resources are stored online in your NSTA Library.
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the last of four Science Objects in the Cell Structure and Function SciPack. It explores protein molecules at a more in-depth level. The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. DNA is the blueprint that determines the order of amino acids for any given protein that differs somewhat with each species. Protein molecules are long, usually folded chains composed of combinations from 20 different kinds of amino acid molecules. The function of each protein depends on its specific sequence of amino acids and the shape the chain takes as a consequence of attractions between the chain's parts. The action of the proteins is catalyzed by a set of enzymes (also proteins). Some of the assembled molecules assist in replicating genetic information, repairing cell structures, helping other molecules to get in or out of the cell, and generally in catalyzing and regulating molecular interactions. In specialized cells, other protein molecules may carry oxygen, affect contraction, respond to outside stimuli, or provide material for hair, nails, and other body structures. In still other cells, assembled molecules may be exported to serve as hormones, antibodies, or digestive enzymes.