monomer

Examples of monomer in the following topics:

• Dehydration Synthesis

  • In doing so, monomers release water molecules as byproducts.
  • In a dehydration synthesis reaction between two un-ionized monomers, such as monosaccharide sugars, the hydrogen of one monomer combines with the hydroxyl group of another monomer, releasing a molecule of water in the process.
  • The removal of a hydrogen from one monomer and the removal of a hydroxyl group from the other monomer allows the monomers to share electrons and form a covalent bond.
  • When the monomers are ionized, such as is the case with amino acids in an aqueous environment like cytoplasm, two hydrogens from the positively-charged end of one monomer are combined with an oxygen from the negatively-charged end of another monomer, again forming water, which is released as a side-product, and again joining the two monomers with a covalent bond.
  • As additional monomers join via multiple dehydration synthesis reactions, the chain of repeating monomers begins to form a polymer.

• Types of Biological Macromolecules

  • Examples of these monomers and polymers can be found in the sugar you might put in your coffee or tea.
  • Regular table sugar is the disaccharide sucrose (a polymer), which is composed of the monosaccharides fructose and glucose (which are monomers).
  • If we were to string many carbohydrate monomers together we could make a polysaccharide like starch.
  • The prefixes "mono-" (one), "di-" (two),and "poly-" (many) will tell you how many of the monomers have been joined together in a molecule.
  • Lipids are not polymers, because they are not built from monomers (units with similar composition).

• Carbohydrate Molecules

  • Lactose is a disaccharide consisting of the monomers glucose and galactose.
  • It is made up of monomers of glucose.
  • Cellulose is made up of glucose monomers that are linked by β 1-4 glycosidic bonds .
  • Every other glucose monomer in cellulose is flipped over, and the monomers are packed tightly as extended long chains.
  • Sucrose is formed when a monomer of glucose and a monomer of fructose are joined in a dehydration reaction to form a glycosidic bond.

• Hydrolysis

  • Hydrolysis reactions result in the breakdown of polymers into monomers by using a water molecule and an enzymatic catalyst.
  • Polymers are broken down into monomers in a process known as hydrolysis, which means "to split water," a reaction in which a water molecule is used during the breakdown .
  • In the hydrolysis reaction shown here, the disaccharide maltose is broken down to form two glucose monomers with the addition of a water molecule.
  • This is the reverse of the dehydration synthesis reaction joining these two monomers.
  • This is the reverse of the dehydration synthesis reaction joining these two monomers.

• Connecting Other Sugars to Glucose Metabolism

  • The glycogen is hydrolyzed into the glucose monomer, glucose-1-phosphate (G-1-P), if blood sugar levels drop.
  • The catabolism of sucrose breaks it down to monomers of glucose and fructose.

• Types and Functions of Proteins

  • Proteins (a polymer) are macromolecules composed of amino acid subunits (the monomers).
  • These biosynthetic enzymes include DNA Polymerase, which catalyzes the synthesis of new strands of the genetic material before cell division; fatty acid synthetase, which the synthesis of new fatty acids for fat or membrane lipid formation; and components of the ribosome, which catalyzes the formation of new polypeptides from amino acid monomers.

• Amino Acids

  • Amino acids are the monomers that make up proteins.
  • Any reaction that combines two monomers in a reaction that generates H2O as one of the products is known as a dehydration reaction, so peptide bond formation is an example of a dehydration reaction.

• DNA and RNA

  • DNA and RNA are made up of monomers known as nucleotides.
  • The phosphodiester linkage is not formed by simple dehydration reaction like the other linkages connecting monomers in macromolecules: its formation involves the removal of two phosphate groups.

• Strategies Used in Sequencing Projects

  • The chain termination method involves DNA replication of a single-stranded template with the use of a primer and a regular deoxynucleotide (dNTP), which is a monomer, or a single unit, of DNA.
  • The ddNTPs are monomers that are missing a hydroxyl group (–OH) at the site at which another nucleotide usually attaches to form a chain .

• Levels of Organization of Living Things

  • Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules).