PROTEINS Proteins are amino acid in a chain, in which small or large amino acids are bonded together to make different sizes of peptides. Short peptides are called oligopeptides, while long peptides are called polypeptides or proteins. Proteins are largely structural aspects of the cells, but some an be hormones, receptor molecules, transport molecules, and enzymes. Amino acids are organic molecules with two specific groups: a carboxyl COOH group and an amino group or NH2 group. These are attached to what’s called the alpha carbon. Added also to this carbon atom is a side chain, which differs according to the amino acid. The simplest side chain is just hydrogen molecules attached to the alpha carbon. Figure 33 shows the different amino acids found in nature:
Figure 33.
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