Skip to main content

CARBOHYDRATES and their sources

CARBOHYDRATES

Introduction

Carbohydrates occur abundantly in living organisms. They are found in all organisms and in almost all parts of the cell.

Meaning

  • The word carbohydrate literally means hydrated carbon. They are composed of carbon, hydrogen and oxygen, the ratio of hydrogen and oxygen is the same as in water.
  • Their general formula is Cx(H2O)y, where x and y are the whole number from three to many thousands whereas y may be the same or different whole number.

Definition

  • Chemically carbohydrates are defined as polyhydroxy aldehydes or ketones or complex substances, which on hydrolysis yield polyhydroxy aldehyde or ketone subunits. (Hydrolysis involves the breakdown of large molecules into smaller ones utilizing water molecules).
Source
The source of carbohydrates are green plants. These are the primary products of photosynthesis. Other compounds of plants are produced from carbohydrates by various chemical changes.
Cellulose of wood, cotton, and paper, starches present in cereals, root tubers, cane sugar and milk sugar are all examples of carbohydrates.

Conjugated Molecules of Carbohydrates

Carbohydrates in cell combine with
  • Protein forming glycoproteins
  • Lipids forming glycolipids

Glycoproteins and glycolipids have structural role in the extracellular matrix of animals and bacterial cell wall. Both these conjugated molecules are components of biological membranes.

Comments

Post a Comment

Popular posts from this blog

Mr chips important short questions.

Chapter#1 Question # 1:How does a person spend his time in old age after retirement? Answer : After retirement when a person becomes old, he has nothing to do. His time seems to pass like lazy cattle moving across a landscape(valley). Question # 2:Why did Chips keep on adjusting his timetable according to the school bells even after the retirement? Answer : After spending more than forty three(43) years at Brookfield, it was not possible for Chips to break his ties with school. He began to live across the road and Mrs. Wickets. That's why it was possible for Chips to keep on adjusting his timetable according to the school bells. Question # 3:How did Chips voice sound in old age? Answer : Although Chips had become old yet he did not loose the zeal and zeast for the life. So his voice remained resonant and lively even in his old age. Question # 4:What did Chips do before going to the bed? Answer : Chips was spending a pleasant and placid time at Mrs. Wickets after his retirem...
Post a Comment
Read more

DISPLACMENT, DISTANCE, SPEED, VELOCITY AND ACCELERATION

Displacement: Shortest distance between two points is called displacement                                                                OR The displacement is a change in the position of body form its initial position to final position Unit:  SI unit of displacement is metre (m)                    Dimension:             The dimension of displacement is [L] VELOCITY: The time rate of change of displacement is known as velocity. It is a vector quantity. Its direction is along the direction of displacement. Mathematically...
Post a Comment
Read more

Proteins

PROTEINS Introduction Proteins are the most abundant organic compounds to be found in cells and comprise over  50%  of their total dry weight. They are present in all types of cells and in all parts of the cell. Function Proteins perform many functions. Some of their important functions are; They  build many structures  of the cell. All  enzymes  are proteins and in this way they control the whole metabolism of the cell. Some hormones  are also proteins and regulate metabolic processes. Some proteins (e.g.  haemoglobin )   work as carriers and transport specific substances such as oxygen, lipid, metal ions etc. Some proteins called  antibodies , defend the body against pathogens. Blood clotting  proteins prevent the loss of blood from the body after an injury. Movement  of organs and organisms and movement of chromosomes during anaphase of cell division, are caused by proteins. Amino acids as units of protei...
Post a Comment
Read more