A Monomer is a small molecule, that linked together with other small molecules forms a Polymer. The four monomers that are involved in biological processes are Monosaccharide, Amino Acid, Fatty Acid, and Nucleotide.
Monomers link together by dehydration, or forming a molecule of water by the monomers losing 2 hydrogens and an oxygen between them.
Monomers of monosaccharides link together to form simple and compound sugars and carbohydrates, or polysaccharides.
Monomers of Amino Acids link together to form polypeptides, or proteins.
Monomers of Fatty Acids link together to form glycerides, or lipids.
Monomers of Nucleotides link together to form the Nucleic Acids DNA and RNA.
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Ionic Bonds are bonds that occur when electrons are transferred between ions. For example, NaCl - or salt - is held together by ionic bonds. An ion is an atom that has lost or gained an electron.
Covalent bonds happen when atoms share electrons. There are two types of covalent bonds. Polar convalent bonds happen when atoms share electrons unequally like water. Non-polar covalent bonds happen when atoms share electrons equally like in oxygen gas.