( 20622 Reads)
Everything we can see, touch, taste or experience in any other way is made of matter. Matter is made of atoms and they consist of the subatomic particles, protons, neutrons and electrons. Biological compounds are made of matter, just like everything else, but living systems tend to be made of the lighter elements, with C, N, O, H, P and S being the majority. These elements are part of cell structures, and many of theses structures are formed by making polymers. These polymers are made from just a few basic types of molecules: amino acids, sugars, nucleic acids and fatty acids. Sugars are used in structures in the cell, and sometimes decorate proteins and lipids. Nucleic acids are more complex polymers having a backbone made of sugar and phosphorus, with the base giving the nucleic acid its identity. Proteins are polymers of 20 assorted amino acids and they are the biological catalysts of the cell. The sequence of the polymers dictates their structure and subsequently their function, especially for proteins. Finally, lipids are made from glycerol, a polar head group and two long-chain fatty acids. The amphipathic nature of lipids encourages them to assemble into a lipid bilayer and forms the foundation of the cell. In subsequent chapters we will discuss how this chemistry comes together to form the diversity of living organisms we call microbes.
Answer the questions below and then hit the Grade Exam button