The branch of the U.S. government that is composed of the president and all the individuals, agencies, and departments that report to the president, and that is responsible for administering and enforcing the laws that Congress passes.
Proteins are biological polymers composed of amino acids. Amino acids, linked together by peptide bonds, form a polypeptide chain. One or more polypeptide chains twisted into a 3-D shape form a protein. Proteins have complex shapes that include various folds, loops, and curves.
Amino acid molecules are smaller than protein molecules and are inside of the protein molecules. Amino 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.