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 Basic text and talk phone plans generally cost $40-$60 a month. 2  Basic plans typically have a restricted number of talk minutes (often less than 500) and unlimited texting. 3  Basic plans also often include free mobile-to-mobile calls to lines on the same carrier and free nights and weekends. Depending on the plan, text, IM (Instant Messaging), picture and video messaging can also cost extra. 2  Unlimited text messaging typically costs $20 per month. 3  See: How Much Does Text Messaging Cost. 4  There are state and local taxes on monthly plans, but these are generally minimal.