hydrolysis

Examples of hydrolysis in the following topics:

• Hydrolysis

  • Hydrolysis reactions result in the breakdown of polymers into monomers by using a water molecule and an enzymatic catalyst.
  • This is what happens when monosaccharides are released from complex carbohydrates via hydrolysis.
  • This is what happens when amino acids are released from protein chains via hydrolysis.
  • In hydrolysis reactions, a water molecule is consumed as a result of breaking the covalent bond holding together two components of a polymer.
  • Dehydration and hydrolysis reactions are chemical reactions that are catalyzed, or "sped up," by specific enzymes; dehydration reactions involve the formation of new bonds, requiring energy, while hydrolysis reactions break bonds and release energy.

• ATP: Adenosine Triphosphate

  • Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions to harness the energy within the bonds of ATP.
  • Like most chemical reactions, the hydrolysis of ATP to ADP is reversible.
  • Since ATP hydrolysis releases energy, ATP synthesis must require an input of free energy.
  • The calculated ∆G for the hydrolysis of one mole of ATP into ADP and Pi is −7.3 kcal/mole (−30.5 kJ/mol).
  • Cells couple the exergonic reaction of ATP hydrolysis with the endergonic reactions of cellular processes.

• ATP in Metabolism

  • Hydrolysis is the process of breaking complex macromolecules apart.
  • During hydrolysis, water is split, or lysed, and the resulting hydrogen atom (H+) and a hydroxyl group (OH-) are added to the larger molecule.
  • The hydrolysis of ATP produces ADP, together with an inorganic phosphate ion (Pi), and the release of free energy.
  • Water, which was broken down into its hydrogen atom and hydroxyl group during ATP hydrolysis, is regenerated when a third phosphate is added to the ADP molecule, reforming ATP.
  • The energy from ATP can also be used to drive chemical reactions by coupling ATP hydrolysis with another reaction process in an enzyme.

• ATP and Muscle Contraction

  • The energy released during ATP hydrolysis changes the angle of the myosin head into a "cocked" position, ready to bind to actin if the sites are available.

• The Mechanism of Protein Synthesis

  • The energy for the peptide bond formation is derived from GTP hydrolysis, which is catalyzed by a separate elongation factor.
  • The elongation factor eEF1 assists in loading the aminoacyl-tRNA, powering the process through the hydrolysis of GTP.
  • The elongation factor eEF2 assists in the translocation, powering the process through the hydrolysis of GTP.

• Peptide Bonding between Amino Acids

  • The amide bond can only be broken by amide hydrolysis, where the bonds are cleaved with the addition of a water molecule.

• DNA Replication in Prokaryotes

  • ATP hydrolysis is required for this process.

• Control of Catabolic Pathways

  • Note that the first two steps that are regulated occur early in the pathway and involve hydrolysis of ATP.

• Digestive System: Mouth and Stomach

  • The highly-acidic environment also kills many microorganisms in the food and, combined with the action of the enzyme pepsin, results in the hydrolysis of protein in the food.

• Digestive System: Small and Large Intestines

  • Here, hydrolysis of nutrients is continued while most of the carbohydrates and amino acids are absorbed through the intestinal lining.