The cell is the basic structural, functional, and biological unit of all known organisms. A cell is the smallest unit of life. Cells are often called the "building blocks of life". The study of cells is called cell biology, cellular biology, or cytology.

1. THE CELL
Prepared by
Mr.Abhay Rajpoot
HOD (Dep. of Medical Surgical)
abhayrajpoot5591@gmail.com

3. CELL
•A cell is the basic, living, structural and functional unit of
living organisms.
•There are about 200 different types of cells in our body.
•All cells produced by the process of cell division.
•Cell biology is the study of cellular structure and function.
•Structure of the cell is intimately related to its function.

4. PARTS OF ACELL
1. Plasma membrane
2. Cytoplasm
a) Cytosol
b) Organelles
3) Nucleus

5. The plasma membrane
Structure:
• The membrane is composed of proteins and lipids
(phospholipids).
• It bind together by non covalent forces
• The phospholipid molecules have head which is electrically
charged and hydrophilic in nature. A tail which has no charge
and hydrophobic in nature.
• In this layer the sugar molecule is embedded in between
them.

6. Functions
• Protection
• Barrier
• Shape of the cell
• Cell junction
• Cell movement
• Selective permeability
• Impulse transmission

7. Cytoplasm
• The cytoplasm has two components
a) Cytosol:
• It is the fluid portion of cytoplasm that contains water (75-90 %), ions,
amino acids, proteins, lipids, ATPand waste products.
b) Organelles:
1. Ribosomes
2. Endoplasmic reticulum (smooth & rough)
3. Golgi complex
4. Mitochondria
5. Nucleus

8. Ribosomes
• These are tiny granules composed of RNA & protein.
• They synthesize protein from amino acids using RNA.
• When this is present in free units in the cytoplasm, the ribosomes
make proteins for use within the cell.
• Ribosomes are also found on the outer surface of the nuclear envelope
and rough endoplasmic reticulum where they manufacture proteins for
export from the cell.

9. Endoplasmic Reticulum
•It is the series of interconnecting membranous canals in the cytoplasm.
There are 2 types of endoplasmic reticulum
1. Smooth endoplasmic reticulum:
• Here is lack of ribosomes
2. Rough endoplasmic reticulum:
• This is studded with ribosomes that synthesize proteins.

10. Golgi apparatus
• It consist of stack of closely folded flattened membranous sac.
• It present in all cells but is larger in those cells that synthesize and
export proteins.
• The proteins move from ER to golgi apparatus where they are
‘packaged’ into membrane bound vesical called secretory granules.
• The vesicles are stored and when needed more to plasma membrane,
through which the proteins are exported.

11. Nucleus
• Every cell in the body has nucleus, with exception of mature RBC.
• Skeletal muscle and some other cell contain several nuclei.
• It is the larger organelle of the cell and is contained within the nuclear
envelope.
• The nucleus contains body’s genetic
material which directs all metabolic
activities of the cell.
•This consist of 46 chromosomes,
which are made from DNA.

12. Mitochondria
• This is also called ‘Power House’of
cell.
• They are involved in the aerobic
respiration. The process by which
chemical energy is made available in
the cell.
• This energy is in the form of ATP
which release energy when the cell
break it down.
• Synthesis of ATP is most efficient in
the final stage of aerobic respiration.
A process requiring oxygen.

13. Cell Division
There are two types of cell division: mitosis and meiosis.
Most of the time when people refer to “cell division,” they
mean mitosis, the process of making new body cells. Meiosis
is the type of cell division that creates egg and sperm cells.
Mitosis is a fundamental process for life.

15. Cell Cycle
The cell cycle is a four-stage process in which the cell increases in size
(gap 1, or G1, stage), copies its DNA (synthesis, or S, stage), prepares to
divide (gap 2, or G2, stage), and divides (mitosis, or M, stage).

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