Carbohydrates and its classification

1. CARBOHYDRATES
By: Dr Gul Muhammad
Doctor of veterinary Medicine

2. MEDICAL AND BIOLOGICAL
IMPORTANCE
 1. Carbohydrates are the major source of energy for
man. For example, glucose is used in the human body
for energy production.
 2. Some carbohydrates serve as reserve food material in
humans and in plants. For example, glycogen in animal
tissue and starch in plants serves as reserve food
materials.
 3. Carbohydrates are components of several animal
structure and plant structures. In
 animals, carbohydrates are components of skin,
connective tissue, tendons, cartilage and bone. In plants,
cellulose is a component of wood and fiber.

3.  4. Some carbohydrates are components of cell
membrane and nervous tissue.
 5. Carbohydrates are components of nucleic
acids and blood group substances.
 6. Carbohydrates are involved in cell-cell
interaction.
 7. Derivative of carbohydrates are drugs. For
example, a glycoside ouabain is used In
clinical medicine. Streptomycin an antibiotic is
a glycoside.

4.  8. Aminosugars, derivatives of carbohydrates
are components of antibiotics like erythromycin
and carbomycin.
 9. Ascorbic acid, a derivative of carbohydrate is
a water-soluble vitamin.
 10. Bacterial invasion involves hydrolysis of
mucopolysaccharides.
 11. Survival of Antarctic fish in icy environment
is due to presence of anti-freeze glycoproteins
in their blood.

5. Classification of
Carbohydrates
 Carbohydrates are classified into three major
classes based on number of carbon chains
present. They are:
 1. Monosaccharides
 2. Oligosaccharides
 3. Polysaccharides

6. Monosaccharides—“Single”
Sugars
 Hexose sugar
 Glucose
 Fructose
 Galactose
 Pentose sugar
 Deoxyribose
 Ribose

7. Function
 Most important energy source for cells
 Converted to glucose by the liver, then used
for energy production
 Part of DNA, the genetic code in the
chromosomes of cells.
 Part of RNA, needed for protein synthesis
within cells.

8. Disaccharides—“Double”
Sugars
 Sucrose, lactose, and maltose.
 Two hexose sugars combine and form it.

9. Function
 Present in food; digested to monosaccharides,
which are then used for energy production.
 Form “self” antigens on cell membranes;
important to permit the immune system to
distinguish “self” from oreign antigens
(pathogens)

10. Polysaccharides—“Many”
Sugars
 Starches, Glycogen and Cellulose.
 Structure
 Branched chains of glucose molecules
 Highly branched chains of glucose molecules
 Straight chains of glucose molecules

11. Function
 Found in plant foods; digested to
monosaccharides and used for energy
production.
 Storage form for excess glucose in the liver
and skeletal muscles.
 Part of plant cell walls; provides fiber to
promote peristalsis, especially by the colon.