2. DEFINITION OF ABSORPTION
In biology, it refers to the process by which cells
and organs absorb substances through tissue cell.
Absorption describes the process of absorbing or
soaking up something: Sponges are good at water
absorption; dark colors are better for heat
absorption.
Absorptions are two types:
-Physical absorption.
-Chemical absorption
3. DEFINITION OF DIGESTION
The catabolic process in the digestive tract where
ingested food is converted into simpler, soluble and
diffusible substances that can be assimilated by the
body that is called digestion.
Or
The process by which food is broken down into
simple chemical compounds that can be absorbed
and used as nutrients or eliminated by the body is
also called digestion.
4. DEFINITION OF METABOLISM
Metabolism is the whole range of biochemical
processes that occur within a living organism.
Metabolism consists of anabolism and catabolism
The term metabolism is commonly used to refer
specifically to the breakdown of food and its
transformation into energy.
Fig:Energy metabolism
5.
6. CARBOHYDRATE METABOLISM
Carbohydrate metabolism denotes the various
biochemical processes responsible for the
formation, breakdown and interconversion of
carbohydrates in living organisms.
Metabolism of carbohydrate occurs in three steps
such as,-Digestion of Carbohydrate.
-Absorption of digestive end products of
Carbohydrate.
-Distribution throughout the body /Utilization of
Carbohydrate.
7.
8. DIGESTION OF CARBOHYDRATE
The digestive end products of carbohydrate are
monosaccharides and these are obtained by the
following enzymatic reaction:
ptyalin
Carbohydrate
Pancreatic amylase
Dextrin
(in mouth)
Dysaccharides
(in duodenum)
Intestinal amylase
Monosaccharide
9. ABSORPTION OF DIGESTIVE END PRODUCT
OF CARBOHYDRATE
The digestive end products of carbohydrate are
glucose, fructose and galactose which remain in the
lumen of small intestine after complete digestion. These
monosaccharides are absorbed through intestinal
epithelial cells.
Absorption through intestinal mucosa is caused by
phosphorylation in the presence of enzyme
phosphorylase or phosphokinase.
11. After entering into the epithelial cell, these products
are dephosphorylated by phosphatase enzyme and
monoccharadies become free. These free
monoccharides come into blood stream and then
through portal circulation, they go to the liver.
In liver cells these products are again
phosphorylated. If our body needs glucose,then
glycogen are broken down into glucose and further
utilized.
12. The glucose is carried to the systemic circulation and
entered into the tissue by the following steps:
Glucose in liver
Blood circulation
Heart
systemic circulation
Tissue cell
13. UTILIZATION OF CARBOHYDRATE
In tissue cell, glucose is phosphorylated into Glucose -6Phosphate and through and through glycolysis
process,converted into pyruvic acid. This pyruvic acid is
converted into acetyl Co-A.Through TCA cycle, Energy is
produced from acetylCo-A.
Glucokinase
Glucose
Glycolysis
Glucose-6-phosphate
Pyruvic acid
Energy+CO2+H2O
Acetyl Co-A
TCA cycle