carbohydrate

Examples of carbohydrate in the following topics:

• Importance of Carbohydrates

  • Carbohydrates are, in fact, an essential part of our diet; grains, fruits, and vegetables are all natural sources of carbohydrates.
  • Carbohydrates have been a controversial topic within the diet world.
  • Calorie-wise, a gram of carbohydrate provides 4.3 Kcal.
  • Without the consumption of carbohydrates, the availability of "instant energy" would be reduced.
  • Eliminating carbohydrates from the diet is not the best way to lose weight.

• Metabolism of Carbohydrates

  • Organisms break down carbohydrates to produce energy for cellular processes, and photosynthetic plants product carbohydrates.
  • Carbohydrates are one of the major forms of energy for animals and plants.
  • Plants build carbohydrates using light energy from the sun (during the process of photosynthesis), while animals eat plants or other animals to obtain carbohydrates.
  • Plants store carbohydrates in long polysaccharides chains called starch, while animals store carbohydrates as the molecule glycogen.
  • Plants and some other types of organisms produce carbohydrates through the process called photosynthesis.

• Carbohydrate Molecules

  • Carbohydrates can be represented by the stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule.
  • Therefore, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules.
  • The origin of the term "carbohydrate" is based on its components: carbon ("carbo") and water ("hydrate").
  • Carbohydrates are classified into three subtypes: monosaccharides, disaccharides, and polysaccharides.
  • Carbohydrates serve various functions in different animals.

• Fluid Mosaic Model

  • The fluid mosaic model describes the plasma membrane structure as a mosaic of phospholipids, cholesterol, proteins, and carbohydrates.
  • The proportions of proteins, lipids, and carbohydrates in the plasma membrane vary with cell type.
  • Carbohydrates are the third major component of plasma membranes.
  • These carbohydrate chains may consist of 2–60 monosaccharide units and can be either straight or branched.
  • These carbohydrates on the exterior surface of the cell—the carbohydrate components of both glycoproteins and glycolipids—are collectively referred to as the glycocalyx (meaning "sugar coating").

• Types of Biological Macromolecules

  • Biological macromolecules, the large molecules necessary for life, include carbohydrates, lipids, nucleic acids, and proteins.
  • If we were to string many carbohydrate monomers together we could make a polysaccharide like starch.
  • The carbohydrate monosaccharides (fructose and glucose) are joined to make the disaccharide sucrose.
  • Carbohydrates, proteins, and nucleic acids are built from small molecular units that are connected to each other by strong covalent bonds.

• The Energy Cycle

  • Whether the organism is a bacterium, plant, or animal, all living things access energy by breaking down carbohydrate molecules.
  • But if plants make carbohydrate molecules, why would they need to break them down, especially when it has been shown that the gas organisms release as a "waste product" (CO2) acts as a substrate for the formation of more food in photosynthesis?
  • Photosynthesis absorbs light energy to build carbohydrates in chloroplasts, and aerobic cellular respiration releases energy by using oxygen to metabolize carbohydrates in the cytoplasm and mitochondria.

• Digestion and Absorption

  • In order for nutrients (carbohydrates, lipids, vitamins) to be absorbed for energy, food must undergo chemical and mechanical digestion.
  • The digestion of carbohydrates begins in the mouth.
  • As the food travels through the esophagus to the stomach, no significant digestion of carbohydrates takes place.
  • The next step of carbohydrate digestion takes place in the duodenum.
  • Digestion of carbohydrates is performed by several enzymes.

• Food Energy and ATP

  • The primary source of energy for animals is carbohydrates, primarily glucose: the body's fuel.
  • The digestible carbohydrates in an animal's diet are converted to glucose molecules and into energy through a series of catabolic chemical reactions.
  • ATP is produced by the oxidative reactions in the cytoplasm and mitochondrion of the cell, where carbohydrates, proteins, and fats undergo a series of metabolic reactions collectively called cellular respiration .

• Metabolic Pathways

  • The processes of making and breaking down carbohydrate molecules illustrate two types of metabolic pathways.
  • For example, one metabolic pathway for carbohydrates breaks large molecules down into glucose.
  • Another metabolic pathway might build glucose into large carbohydrate molecules for storage.

• Dehydration Synthesis

  • Three of the four major classes of biological macromolecules (complex carbohydrates, nucleic acids, and proteins), are composed of monomers that join together via dehydration synthesis reactions.
  • Complex carbohydrates are formed from monosaccharides, nucleic acids are formed from mononucleotides, and proteins are formed from amino acids.
  • These three are polysaccharides, classified as carbohydrates, that have formed as a result of multiple dehydration synthesis reactions between glucose monomers.