Skip to main content

Functions of Cell Membrane

Functions of Cell Membrane
1. Mechanical Support
It provides mechanical support to the protoplasm.
2. External Form
It provides external form to cell.
3. Transportation
Transport of materials, which is vital for cell, occurs through cell membrane. It offers a barrier between the cell contents and their environment allowing only selective substances to pass through it. Thus it is also known as differentially permeable or selectively permeable membrane.
4. Regulation of Materials
It regulates the flow of materials and ions to maintain definite gradient across it.
  • The substances, which are lipid soluble, cross it more easily.
  • Many small gas molecules, water, glucose etc being neutral can easily cross.
  • Ions, beings charged particles have some difficulty in crossing.
5. Active Transport
Many substances, which are not needed, enter the cell by passive transport. These are then pushed out by active transport. The energy for this transport is provided by ATP.
6. Endocytosis
In many animal cells, the cell membrane helps to take in materials by infoldings in the form of vacuoles. This type of intake is termed as endocytosis. It may be;
  • Phagocytosis – ingestion of solid material.
  • Pinocytosis – ingestion of liquid material.
7. Conduction
In neuron (nerve cells), the cell membrane transmits nerve impulse from one part of the body to the other to keep coordination.

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