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.
1 Most modern fax machines easily share a voice phone line for low-volume faxing -- but this ties up the phone line while faxing. 2  High volume faxing may require a separate fax-only phone line, at a typical cost of $35-$45 monthly plus any long-distance charges.