The subunits of proteins are called  amino acids. Amino acid molecules are smaller than protein  molecules and are inside of the protein molecules.        Aminâ¦o acids are joined together by peptide bonds where the -COOH  group and the -NH2 group of two consecutive amino acids bond with  the loss of a water molecule.
How Much Does USPS Certified Mail Cost for 2017 The cost for sending by Certified Mail is $3.35. This was the amount set on January 22, 2017 by the post office. Five cents over the rate set in 2016. Certified is a fee that is independent of mailing or postage, And if the sender chooses to mail with an accompanying paper Return Receipt, a $2.75 fee applies (up $.05 over 2016). For an electronic receipt, just over half that much at $1.45.
  Your cost at the window will be the postage cost of sending your letter (which must be sent either First-Class Mail or Priority Mail), plus the Certified Mail fee of $2.65, plus a Return Receipt fee, if you desire this service, of $0.85 for email confirmation or $2.15 for confirmation by mail. A certified letter should be written just as any other business letter, but you should note above the name and address of the person to whom it is addressed Sent Certif â¦ ied Mail, Article No. *********** The Article Number should correspond to the Certified Mail Receipt form (PS Form 3800) from the USPS.