For Nursing Students

1. Biochemistry
for
B.Sc.Nursing
CARBOHYDRATES

2.  Define
 Classify
 Function
 Occurane

3.  Carbohydrates may be defined as
polyhydroxy aldehydes or ketones or
compounds which produce them on
hydrolysis.

4.  Carbohydrates are primarily composed of C, H
& O.
 It mean "hydrates of carbon".
 Some of the carbohydrates posses the
empirical formula (CH2O)n, where n≥3.
 However there is several non-carbohydrates
substances e.g. acetic acid (C2H4O2), lactic
acid (C3H6O3), which also appears as hydrates
of carbon.
 Further some of the hydrates of carbon e.g.
rhamnohexose (C7H14O6), don not satisfy the
formula.

5.  The carbohydrates are widespread especially
in:
 Grains,
 Fruits and
 Juices of various plants can sugar and
 Sucrose is present in the nector of flowers in
fruits.
 Carbohydrates and their derivatives are present
in all animal tissue and tissue fluids, blood and
milk.

6.  They are classified as:
 Monosaccharide
 Oligosaccharides
 Polysaccharides

7.  Monosaccharide is the simplest group of
carbohydrates and is often referred to as
simple sugar.
 They have the general formula Cn(H2O)n, and
they cannot be further hydrolyzed.
 The monosaccharide is divided into different
categories:

8.  Aldoses:
 When the functional group in monosaccharide is
an aldehydes , they are known as aldose.
 e.g. glyceraldehydes, glucose.
 Ketoses:
 When the functional group in monosaccharide is
a keto , they are known as ketoses.
 e.g. fructose, dihydroxyacetone.

9.  Trioses (3C)
 Tetrose (4C)
 Pentose (5C)
 Hexose (6C) &
 Heptose (7C)

10.  Glyceraldehyde : aldo triose
 Dihydrooxyacetone: keto triose
 Erythrose: aldo tetrose
 Ribose: aldo pentose
 Ribulose: Xylulose : keto pentose
 Glucose, Galactose, Mannose : aldo hexoses
 Fructose: keto hexose

11.  Oligosaccharides contains 2-10
monosaccharide molecules which are
liberated on hydrolysis.
 Based on the number of monosaccharide
units present, the oligosaccharides are
further subdivided.

12.  The general formula is Cn(H2O)n-1.
Disaccharides on hydrolysis produce two
molecules of the same or different
monosaccharide.
 The other important oligosaccharides include
tri-. Tetra-, or pentasaccharides,
respectively containing 2, 4 or 5
monosaccharide units.
 Examples of disaccharides: Maltose,
Isomaltose, Lactose, Sucrose, Trehalose

13.  Polysaccharides are polymers of monosaccharide
units with high molecular weight.
 They are usually tasteless and form colloids with
water. Polysaccharides are of two types:
 Homopolysaccharide: Made up of only one types
of monosaccharides. They are starch, Glycogen,
Dextrins, Cellulose, Inulin
 Heteropolysaccharide: Made up of 2 or more
types of monosaccharides. They are Hyaluronic
acid, Chondroitin sulphate, Heparin, Keratan
Sulfate, Heparan Sulfate and Dematan sulfate.

14.  Most abundant dietary source of energy for
all organism.
 Are precursors for many organic compounds
(fats, amino acids).
 It participate in the structure of cell
membrane and cellular functions such as cell
growth, adhesion and fertilization.
 Are structural components of many organism
(insects, microorganism).
 It also serve as the storage form of energy to
meet the immediate energy demands of the
body.

15. Sugar Monosaccharide Occurrence
Trioses
Glyceraldehyde
Dihydroxyacetone
Found in cells as phosphate.
Tetroses D-Erythrose Widespread
Penoses
D-Ribose
D-Deoxyribose
D-Ribulose
D-Xylose
D-Lyxose
Widespread as a constituent of RNA &
Nucleotides
As a constituent of DNA
Produced during metabolism
As a constituent of glycoproteins.
Heart muscles
Hexoses
D-Glucose
D-Mannose
D-Fructose
As a constituent of starch, glycogen,
cellulose, maltose, lactose, sucrose.
Found in plant polysaccharide.
Fruits & honey, as a constituent of sucrose
and inulin
Heptoses D-Sedoheptulose Found in plants.
Di-saccharide Occurrence
Sucrose As a constituents of cane sugar & beet sugar, pineapple.
Lactose Milk sugar
Maltose Product of starch hydrolysis, occurs in germinating seeds.