oxidation

Examples of oxidation in the following topics:

• Electrons and Energy

  • The transfer of electrons between molecules via oxidation and reduction allows the cell to transfer and use energy for cellular functions.
  • The removal of an electron from a molecule via a process called oxidation results in a decrease in the potential energy stored in the oxidized compound.
  • These compounds can be easily reduced (that is, they accept electrons) or oxidized (they lose electrons).
  • When electrons are removed from a compound, the compound is oxidized.
  • In the above equation, NAD+ is an oxidizing agent and RH is oxidized to R.

• The Energy-Releasing Steps of Glycolysis

  • The sixth step in glycolysis oxidizes the sugar (glyceraldehyde-3-phosphate), extracting high-energy electrons, which are picked up by the electron carrier NAD+, producing NADH.
  • The continuation of the reaction depends upon the availability of the oxidized form of the electron carrier NAD+.
  • Thus, NADH must be continuously oxidized back into NAD+ in order to keep this step going.
  • In an environment without oxygen, an alternate pathway (fermentation) can provide the oxidation of NADH to NAD+.
  • (This is an example of substrate-level phosphorylation. ) A carbonyl group on the 1,3-bisphosphoglycerate is oxidized to a carboxyl group, and 3-phosphoglycerate is formed.

• Peroxisomes

  • Peroxisomes neutralize harmful toxins and carry out lipid metabolism and oxidation reactions that break down fatty acids and amino acids.
  • They also carry out oxidation reactions that break down fatty acids and amino acids.
  • Free radicals are reactive because they contain free unpaired electrons; they can easily oxidize other molecules throughout the cell, causing cellular damage and even cell death.

• Chemiosmosis and Oxidative Phosphorylation

  • The production of ATP using the process of chemiosmosis in mitochondria is called oxidative phosphorylation.
  • In oxidative phosphorylation, the hydrogen ion gradient formed by the electron transport chain is used by ATP synthase to form ATP.

• Transforming Chemical Energy

  • The nutrients broken down through cellular respiration lose electrons throughout the process and are said to be oxidized.
  • When oxygen is used to help drive the oxidation of nutrients the process is called aerobic respiration.
  • Several prokaryotes and a few eukaryotes use an inorganic molecule other than oxygen to drive the oxidation of their nutrients in a process called anaerobic respiration.

• Electron Transport Chain

  • The electron transport chain uses the electrons from electron carriers to create a chemical gradient that can be used to power oxidative phosphorylation.
  • Oxidative phosphorylation is a highly efficient method of producing large amounts of ATP, the basic unit of energy for metabolic processes.
  • As a result, the iron ion at its core is reduced and oxidized as it passes the electrons, fluctuating between different oxidation states: Fe2+ (reduced) and Fe3+ (oxidized).

• Citric Acid Cycle

  • If this transfer does not occur, the oxidation steps of the citric acid cycle also do not occur.
  • In step three, isocitrate is oxidized, producing a five-carbon molecule, α-ketoglutarate, together with a molecule of CO2 and two electrons, which reduce NAD+ to NADH.
  • Steps three and four are both oxidation and decarboxylation steps, which release electrons that reduce NAD+ to NADH and release carboxyl groups that form CO2 molecules. α-Ketoglutarate is the product of step three, and a succinyl group is the product of step four.
  • The last step in the citric acid cycle regenerates oxaloacetate by oxidizing malate.
  • Through a series of steps, citrate is oxidized, releasing two carbon dioxide molecules for each acetyl group fed into the cycle.

• Importance of Glycolysis

  • Glycolysis is the first pathway of cellular respiration that oxidizes glucose molecules.
  • It is followed by the Krebs cycle and oxidative phosphorylation to produce ATP.

• Abiotic Factors Influencing Plant Growth

  • It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through chemosynthesis, which uses the oxidation or reduction of chemical compounds as its source of energy.
  • It is calculated as the total amount of carbon fixed per year minus the amount that is oxidized during cellular respiration.

• The Nitrogen Cycle

  • Human activity can release nitrogen into the environment by two primary means: the combustion of fossil fuels, which releases different nitrogen oxides, and the use of artificial fertilizers in agriculture, which are then washed into lakes, streams, and rivers by surface runoff.
  • Atmospheric nitrogen is associated with several effects on earth's ecosystems, including the production of acid rain (as nitric acid, HNO3) and greenhouse gas (as nitrous oxide, N2O), potentially causing climate change.