Proteins are made from long chains of smaller molecules called amino acids. These long chains are folded into particular shapes. This is important in relation to how antibodies and enzymes work. Enzymes are biological catalysts. There are optimum temperatures and pH values at which their activity is greatest.
It costs just $0.25 to send a text message from the U.S. to an international number. For customers who frequently send text messages to family or friends overseas, AT&Tâs International Long Distance Messaging package includes 100 text messages sent from the U.S. for $10 a month.
Typical costs: 1  Basic phone service that includes unlimited local calls generally cost $15-$30 per month, depending on additional features. 2  Home phone service plans that include local and long-distance calling cost $30-$45 per month. 3  Some phone companies connect calls on high-speed Internet connections.