Governments usually borrow by issuing securities such as government bonds and bills. Governments create debt by issuing government bonds and bills. Preferred stocks share some of the characteristics of fixed interest bonds. This allows lower interest rates for a broader class of assets beyond government bonds. The states are prohibited from taxing income from federal bonds or other obligations. Saturated hydrocarbons are hydrocarbons having only single covalent bonds between their carbons. Pairs of electrons located between atoms represent covalent bonds. The gross amount of CDSs far exceeds all "real" corporate bonds and loans outstanding. This caused a cross default on other dollar bonds. It also helps institutions who are holders of corporate bonds. Radicals form by breaking of covalent bonds by homolysis. Ionic bonds may be seen as extreme examples of polarization in covalent bonds. It binds to cytosine through three hydrogen bonds. This is also useful for describing the chemical bonds that hold atoms together. Proteins are polymer chains made of amino acids linked together by peptide bonds.