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• Carbohydrates

  · Normally called sugars and starches, are polyhydroxy aldehydes or ketones, or compounds that can be hydrolyzed to them
• · Disaccharides are composed of two monosaccharide units joined together
• · Polysaccharides are composed of three or more monosaccharide units joined together
• Carbohydrates · Synthesized in green plants by photosynthesis, whereby energy from the sun is stored as chemical energy in carbohydrates.
• Carbohydrates · In the body, they are used for bursts of energy needed during exercise in the form of glucose
• Sources of Carbohydrates

  · Sucrose [table sugar];

  · Glucose;

  · Fructose;

  · Lactose;

  · Maltose; and

  · Starches (found in pasta, bread, and grains). These carbohydrates can be digested by the body and provide energy for cells
• There are other carbohydrates that the human body doesn't digest, including insoluble fiber

  · Cellulose from plants; and

  · Chitin from insects and other arthropods

  Unlike sugars and starches, these types of carbohydrates don't contribute calories to the human diet
• Glucose energy is stored as glycogen, with the majority of it in the muscle and liver
• Monosaccharides


  Simplest Carbohydrates
• Monosaccharides


  • Generally have 3 to 6 C atoms in a chain
  • Have an Aldehyde or Ketone ending
  • Have many –OH groups
• Monosaccharides


  Sweet tasting, but their relative sweetness varies greatly
• Monosaccharides


  • They are polar compounds with high melting points
  • Presence of polar functional groups capable of hydrogen bonding makes them very water soluble
• Monosaccharides by number of C atoms


  • Triose (3 C's)
  • Tetrose (4 C's)
  • Pentose (5 C's)
  • Hexose (6 C's)
• Aldose


  Aldehyde Monosaccharides
• Ketose


  Ketone Monosaccharides
• Glyceraldehyde


  Simplest Aldose
• Dihydroxyacetone


  Simplest Ketose
• Monosaccharides are constitutional isomers of each other, sharing the formula C3H6O3
• · The most abundant Monosaccharide is D-glucose, also called Dextrose

  · They are constitutional isomers of each other, sharing the formula C3H6O3
• Carbohydrates


  Also called Carbs, defined as aldehydic or ketonic compounds with some number of oxydrilic groups (so polyhydroxy aldehydes or ketones as well)
• Carbohydrates


  • Many of them, but not all, have general formula (CH2O)n
• Monosaccharides

  · Or simply sugars are formed by only one Polyhydroxy Aldehydic or Ketonic unit
• Oligosaccharides


  Formed by short chains of monosaccharide units (from 2 to 20) linked one to the next by chemical bonds, called Glycosidic Bonds
• Most abundant Oligosaccharides

  • Disaccharides
  • Sucrose (common table sugar)
  • Lactose
  • Maltose
• Polysaccharides

  · Polymers consisting of 20 to 107 Monosaccharide units; they differ from each other for the Monosaccharides recurring in the structure, for the length and the degree of branching of chains, or for the type of links between units
• · Polysaccharides are present, in vertebrates there is only a small number
• Homopolysaccharides

  · Those polysaccharides that contain only one type of Monosaccharide as Starch (D-Glucose), Glycogen (a-D-Glucose), and Chitin (N-Acetyl-D-Glucosamine)
• Heteropolysaccharides

  · Contain two or more different kinds like Hyaluronic Acid (D-Glucuronic Acid and N-Acetyl-D-Glucosamine)
• On the basis of their degree of Polymerization, they can be classified as:

  Simple: Mono- and Disaccharides (also known as “Sugars”)  and Tri- and Tetrasaccharides (Oligosaccharides);

  Complex: Polysaccharides
• · Glucose

  · Fructose

  · Galactose?

  Monosaccharides
• · Glucose

  · Fructose

  · Galactose?

  Monosaccharides
• · (Glucose + Fructose)?


  sucrose
• · (Glucose + Galactose)?

  lactose
• (Glucose + Glucose)?


  maltose
• · Sucrose (Glucose + Fructose)

  · Lactose (Glucose + Galactose)

  · Maltose (Glucose + Glucose)?

  Disaccharides
• · Starch (D-Glucose)

  · Chitin (N-Acetyl-D-Glucosamine)

  · Cellulose (β-Glucose)?

  Polysaccharides
• · Galactose is one of the components of the disaccharide lactose.
• · Patients with Galactosemia lack an enzyme needed to metabolize Galactose, which accumulates and causes Cataracts and Cirrhosis
• · Fructose is one of the components of the Disaccharide Sucrose
• · Ketohexose found in honey and almost twice as sweet as table sugar with the same number of calories per gram