Carbohydrate
1
, Carbohydrate COH
I. Definition:
Carbohydrates are aldehyde or ketone
derivatives of polyhydric alcohols or any
substance derived from them.
2
,II. Importance of carbohydrates:
Carbohydrates are widely distributed both in plants and in
animal tissues. In plants, they are produced by
photosynthesis. Carbohydrates constitute about 60% of
our diet. They are important for:
A. Energy production e.g. glucose.
B. Formation of structural elements in animal and plant
cells.
C. Formation of glycolipids (carbohydrates combined
with lipids) and glycoproteins (carbohydrates combined
with protein); both enter in the structure of cell
membrane and formofthe
III. Classification ground substances between
carbohydrates:
tissues.
A. Monosaccharides: contain one sugar unit.
B. Disaccharides: contain two sugar units.
C. Oligosaccharides: contain 3 - 10 sugar units.
D. 3Polysaccharides: contain more than 10 sugar units.
, IV. Monosaccharides (glycoses):
A. They are the simplest units of carbohydrate i.e. on hydrolysis, they
can not
give a simpler form. The general formula is Cn(H2O)n.
B. Naming (nomenclature) of monosaccharides:
1. According to the presence of aldehyde or ketone group:
a) Aldoses: monosaccharides containing aldehyde group (-CHO). The
suffix -ose means sugar.
b) Ketoses: monosaccharides containing ketone group (-C=O).
2. According to the number of carbon atoms:
a) Trioses: monosaccharides containing 3 carbons.
b) Tetroses: monosaccharides containing 4 carbons.
c) Pentoses: monosaccharides containing 5 carbons.
d) Hexoses: monosaccharides containing 6 carbons.
e) Heptoses: monosaccharides containing 7 carbons.
3. According to both presence of aldehyde or ketone groups and
number of carbon atoms:
a) 4Aldotrioses and ketotrioses.
b) Aldotetroses and ketotetroses.
1
, Carbohydrate COH
I. Definition:
Carbohydrates are aldehyde or ketone
derivatives of polyhydric alcohols or any
substance derived from them.
2
,II. Importance of carbohydrates:
Carbohydrates are widely distributed both in plants and in
animal tissues. In plants, they are produced by
photosynthesis. Carbohydrates constitute about 60% of
our diet. They are important for:
A. Energy production e.g. glucose.
B. Formation of structural elements in animal and plant
cells.
C. Formation of glycolipids (carbohydrates combined
with lipids) and glycoproteins (carbohydrates combined
with protein); both enter in the structure of cell
membrane and formofthe
III. Classification ground substances between
carbohydrates:
tissues.
A. Monosaccharides: contain one sugar unit.
B. Disaccharides: contain two sugar units.
C. Oligosaccharides: contain 3 - 10 sugar units.
D. 3Polysaccharides: contain more than 10 sugar units.
, IV. Monosaccharides (glycoses):
A. They are the simplest units of carbohydrate i.e. on hydrolysis, they
can not
give a simpler form. The general formula is Cn(H2O)n.
B. Naming (nomenclature) of monosaccharides:
1. According to the presence of aldehyde or ketone group:
a) Aldoses: monosaccharides containing aldehyde group (-CHO). The
suffix -ose means sugar.
b) Ketoses: monosaccharides containing ketone group (-C=O).
2. According to the number of carbon atoms:
a) Trioses: monosaccharides containing 3 carbons.
b) Tetroses: monosaccharides containing 4 carbons.
c) Pentoses: monosaccharides containing 5 carbons.
d) Hexoses: monosaccharides containing 6 carbons.
e) Heptoses: monosaccharides containing 7 carbons.
3. According to both presence of aldehyde or ketone groups and
number of carbon atoms:
a) 4Aldotrioses and ketotrioses.
b) Aldotetroses and ketotetroses.
