carbohydrates

Examples of carbohydrates in the following topics:

• Oxygenic Photosynthesis

  • Carbon fixation is a redox reaction, so photosynthesis needs to supply both a source of energy to drive this process, and the electrons needed to convert carbon dioxide into a carbohydrate, which is a reduction reaction.
  • However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.The general equation for photosynthesis is therefore:2n CO2 + 2n DH2 + photons → 2(CH2O)n + 2n DOCarbon dioxide + electron donor + light energy → carbohydrate + oxidized electron donor.In oxygenic photosynthesis water is the electron donor and, since its hydrolysis releases oxygen, the equation for this process is:2n CO2 + 4n H2O + photons → 2(CH2O)n + 2n O2 + 2n H2Ocarbon dioxide + water + light energy → carbohydrate + oxygen + waterOften 2n water molecules are cancelled on both sides, yielding:2n CO2 + 2n H2O + photons → 2(CH2O)n + 2n O2carbon dioxide + water + light energy → carbohydrate + oxygen

• Fermentation Without Substrate-Level Phosphorylation

  • Fermentation is the process of extracting energy from the oxidation of organic compounds such as carbohydrates.
  • Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound.
  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.

• Types of Catabolism

  • A simplified schematic of the catabolism of carbohydrates, proteins and fats is shown in .
  • Carbohydrate catabolism is the breakdown of carbohydrates into smaller units.
  • Carbohydrates are usually taken into cells once they have been digested into monosaccharides.
  • Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures.
  • A simplified outline of the catabolism of proteins, carbohydrates and fats

• Fermented Foods

  • Fermentation is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using microorganisms.
  • Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions.

• Pyruvic Acid and Metabolism

  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.
  • Pyruvate can be converted into carbohydrates via gluconeogenesis, to fatty acids or energy through acetyl-CoA, to the amino acid alanine, and to ethanol.
  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.

• Growth Terminology

  • An autotroph, which means self-feeding or producer, is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances present in its surroundings.
  • They use compounds formed by autotrophs (such as carbohydrates, fatty acids, and alcohols) as their food.

• Polysaccharide Biosynthesis

  • Polysaccharides are long carbohydrate molecules of repeated monomer units joined together by glycosidic bonds.
  • Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as phosphoenolpyruvate (PEP).

• Mycorrhiza

  • This mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose.
  • The carbohydrates are translocated from their source (usually leaves) to root tissue and on to the plant's fungal partners.

• Acetyl CoA and the Citric Acid Cycle

  • The citric acid cycle, shown in —also known as the tricarboxylic acid cycle (TCA cycle) or the Krebs cycle—is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate—derived from carbohydrates, fats, and proteins—into carbon dioxide.
  • The citric acid cycle, or Krebs cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidization of acetate—derived from carbohydrates, fats, and proteins—into carbon dioxide.

• Nonthermophilic Crenarchaeota

  • The cells are organtrophic, using amino acids, organic acids, or carbohydrates for energy.