The fluid mosaic model proposes that the cell membrane is composed of a lipid bilayer with proteins embedded within it. This gives the membrane a fluid and mosaic-like structure. The lipid bilayer consists of phospholipids, glycolipids, and sterols like cholesterol. Proteins make up 30% of the membrane and include integral proteins embedded in the bilayer and peripheral proteins attached to its surface. Together, the lipids and proteins allow the membrane to be selectively permeable and carry out functions like transport, signaling, and providing the cell with structure and protection.

1. FLUID MOSAIC MODEL
Prepared by:
Sabnam
Paramedical Science(BMLT)
Alisha
Dept. of

2. INTRODUCTIO N
Cell Membrane or Plasma membrane
separates the interior of cells from the
outside environment.
• Composed of a lipid bilayer, including
cholesterol which maintain their fluidity under various temperature
Selectively permeable & helps in transport of substances with the help of
proteins such as integral and peripheral proteins.
• Involved in a variety of cellular process such as Cell adhesion, Ion
conductivity
and Cell Signaling.
• Provide mechanical strength to the cell.

3. ➢ First cell was discovered by Robert Hooke in
1665 using a microscope.
• The cell theory was proposed by Theodor Schwann and Matthias Jakob
Schleiden in the 1830s.
1. All living organisms are composed of one or more cells.
2. The cell is the most basic unit of life.
3. All cells arise only from pre-existing cells.
• The lipid bilayer hypothesis was proposed in 1925 by Gorter and Grendel.
• The most accepted biological model of cell membrane was given by SJ
Singer and G. L. Nicolson in 1972.
History

4. FLUID MOSAIC MODEL
In 1972 SJ Singer and GL Nicolson proposed fluid mosaic model.
• Fluid – Individual phospholipids and some proteins can move sideways
(laterally) in each layer-therefore FLUID
• Mosaic – Range of different proteins resting on the surface on through the
phospholipid layer gives it a mosaic appearance

5. lipids and proteins.
• Carbohydrates are present in very small
amount, predominately as Glycoproteins.
• Composition is notset, but constantly
changing for fluidity and changes in the
environment.
➢ Cell membranes contain a variety of biological molecules, mainly

6. 1. LIPIDS
➢ The cell membranes consists of
three class of amphipathic lipids:
phospholipids, glycolipids and
sterols.
• Carbohydrates are present in very
small amount, predominately as
Glycoproteins.
• Composition is not set, but
constantly changing for fluidity and
changes in the environment

7. 2. Carbohydrates
Plasma membranes also contain
carbohydrates, predominantly
glycoproteins.
• Carbohydrates are located on the
surface of the cell where they
recognize host cells and share
information.
• Viruses and other parasites bind to
these receptors cause an

8. • There are two types of protein found in cell
membrane.
• Integral protein buried in cell (70% of total
protein)
• Peripheral protein - present on of surface of cell
membrane (30% total protein)
➢ PROTEIN

9. FUNCTIONS OF
PLASMA MEMBRANE
Protective: Forms outermost boundary of the cells
Digestive:-Takes in food and excretes waste products.
Selective Permeability:-Helps in transport across the membrane
Contains cell surface receptors (e.g: Glycoprotein receptors present on RBCs).
• Cell Adhesion Molecules (Cadherins) present on the plasma membrane of
certain cells plays an important role in the process of inflammation.
• Junctions: Helps in formation of various types ofjunction (Adherens &
Anchoring) along with the help of cytoskeleton elements.