Carbohydrates

• Monomer - Building block; usually referring to same type of block that makes up something larger.
• Carbohydrate - An essential part of our diet; grains, fruits, and vegetables are all natural sources.
• Carbohydrate - Provide ATP (energy reserve) to the body, particularly through glucose oxidation, a simple sugar.
• Carbohydrates is defined as polyhydroxy aldehydes or ketones (consisting of carbon (C), hydrogen (H), and oxygen (O) atoms).
• collectively called as saccharides (Greek: sakcharon = sugar)
• Monomer is called MONOSACCHARIDE
• Carbohydrates – Lipids = structural components of cell membranes
• Carbohydrates – Proteins = function in a variety of cell-cell and cell-molecule recognition processes
• Major Types of Carbohydrates

  1. Simple Carbohydrates
  2. Complex Carbohydrates
• Simple Carbohydrates: Monosaccharides & Disaccharides
• Complex Carbohydrates: Oligosaccharides & Polysaccharides
• MONOSACCHARIDES - Smallest unit that make up a carbohydrate; Building blocks of disaccharides and polysaccharides
• MONOSACCHARIDES - Contains a single polyhydroxy aldehyde or polyhydroxy ketone unit
• Identify the ff. Monosaccharides

  A) Glucose

  B) Fructose

  C) Galactose

  
• Identify the ff. examples

  A) Glucose

  B) Fructose

  C) Galactose

  
• Monosaccharide + Monosaccharide = Disaccharide
• Identify the number of carbon atoms

  A) triose

  B) tetrose

  C) pentose

  D) hexose

  E) hexose

  
• Hexoses (6 carbon atoms)

  1. Glucose - Physiologic sugar/dextrose/blood sugar/grape sugar
  2. Fructose/Levulose/Fruit Sugar – sweetest monosaccharide
  3. Galactose - Readily absorbed in the intestine; biosynthesized in mammary gland
  4. Mannose – obtained from oxidation of mannitol
• Pentoses (5 carbon atoms)

  1. Arabinose - found in Gum Arabic/Acacia
  2. Ribose – found in RNA; constituent of Riboflavin
  3. Deoxyribose – found in DNA (5 carbon atoms)
• Structure of Monosaccharides

  1. Fischer Projection - Open chain & 2D structure
  2. Haworth Projection - Closed chain structure
  3. Chair Conformation - Most stable
• Epimers - differ only in configuration at chiral C
• Anomers - if cyclic, differ only in carbon, dissolve in H2O - Mutarotation
• Mutarotation - the cyclic a and b of a sugar in solution are in equilibrium with each other, and can readily be interconverted.
• Blood sugar - is also utilized because glucose is the most important monosaccharide in the blood that the cells used as a primary source of energy.
• Monosaccharides - are classified as aldoses or ketoses on the basis of the type of carbonyl group present.
• Aldose - is a monosaccharide that contains an aldehyde functional group (polyhydroxy aldehydes)
• Ketose - is a monosaccharide that contains a ketone functional group (polyhydroxy ketones)
• A six-carbon monosaccharide with an aldehyde functional group is an aldohexose; a five-carbon monosaccharide with a ketone functional group is a ketopentose.
• DISACCHARIDES - Sugar formed when two monosaccharides are joined by glycosidic linkage.
• Types of Disaccharides:

  1. Sucrose – glucose + fructose; 1-2 linkage (α to β)
  2. Lactose – glucose + galactose; 1-4 linkage (β to β)
  3. Maltose – glucose + glucose; 1-4 linkage (α to β)
• POLYSACCHARIDE - Contains many monosaccharide units covalently bonded to each other (more than 12 and several thousand monosaccharide units)
• POLYSACCHARIDE - Some of the examples are cellulose, starch chitin and glycogen
• POLYSACCHARIDE - Heterogeneous (containing slight modifications of the repeating unit)
• POLYSACCHARIDE is:

  1. Amorphous or even insoluble in water
  2. Homopolysaccharide or Homoglycan
  3. Heteropolysaccharides or Heteroglycans
• Types of Polysaccharides:

  1. Homopolysaccharides – same monomer
  2. Heteropolysaccharides – different monomer
• Homopolysaccharides samples are:

  1. Starch
  2. Glycogen/Animal Starch
  3. Cellulose
• Heteropolysaccharides samples are:

  1. Hyaluronic Acid (vitreous humor)
  2. Chondroitin sulfate
  3. Keratan sulfate (nails)
  4. Dermatan Sulfate (skin
  5. Heparin Sulfate (anticoagulant)
  6. Peptidoglycan (bacterial cell wall)
• OLIGOSACCHARIDES - Contains two to ten monosaccharide units covalently bonded to each other
• Disaccharides are the most common type of oligosaccharides
• OLIGOSACCHARIDES - Associated with proteins and lipids in complexes that have both structural and regulatory functions