isomer

Examples of isomer in the following topics:

• Organic Isomers

  • Molecules that share the same chemical formula but differ in the placement (structure) of their atoms and/or chemical bonds are known as isomers.
  • Structural isomers (such as butane and isobutane ) differ in the placement of their covalent bonds.
  • Molecules that have the same number and type of atoms arranged differently are called isomers.
  • (a) Structural isomers have a different covalent arrangement of atoms.
  • (b) Geometric isomers have a different arrangement of atoms around a double bond.

• Organic Enantiomers

  • Stereoisomers are a type of isomer where the order of the atoms in the two molecules is the same but their arrangement in space is different.
  • Optical isomers are stereoisomers formed when asymmetric centers are present; for example, a carbon with four different groups bonded to it.
  • Enantiomers are two optical isomers (i.e. isomers that are reflections of each other).
  • Every stereocenter in one isomer has the opposite configuration in the other.
  • Compounds that are enantiomers of each other have the same physical properties except for the direction in which they rotate polarized light and how they interact with different optical isomers of other compounds.

• The Energy-Requiring Steps of Glycolysis

  • In the second step of glycolysis, an isomerase converts glucose-6-phosphate into one of its isomers, fructose-6-phosphate.
  • An enzyme that catalyzes the conversion of a molecule into one of its isomers is an isomerase.
  • The fourth step in glycolysis employs an enzyme, aldolase, to cleave 1,6-bisphosphate into two three-carbon isomers: dihydroxyacetone-phosphate and glyceraldehyde-3-phosphate.
  • In the fifth step, an isomerase transforms the dihydroxyacetone-phosphate into its isomer, glyceraldehyde-3-phosphate.
  • Thus, the pathway will continue with two molecules of a single isomer.

• The Energy-Releasing Steps of Glycolysis

  • In the eighth step, the remaining phosphate group in 3-phosphoglycerate moves from the third carbon to the second carbon, producing 2-phosphoglycerate (an isomer of 3-phosphoglycerate).

• Transduction of Light

  • When light hits a photoreceptor, it causes a shape change in the retinal, altering its structure from a bent (cis) form of the molecule to its linear (trans) isomer.

• Carbohydrate Molecules

  • This makes them different molecules despite sharing the same atoms in the same proportions, and they are all isomers of one another, or isomeric monosaccharides.

• Citric Acid Cycle

  • Citrate loses one water molecule and gains another as citrate is converted into its isomer, isocitrate.