CELL STRUCTURE for nursing students.

Cell Structure Simplified Notes for Nursing Students

What is a Cell?

A cell is the basic structural and functional unit of life. All living organisms are made up of cells.
Cells perform important functions such as producing energy, removing waste, and helping the
body grow.

Types of Cells

1. Prokaryotic Cells

•Simple cells without a nucleus
•DNA is freely present in the cytoplasm
•Example: Bacteria

2. Eukaryotic Cells

•Complex cells with a true nucleus
•Contain membrane-bound organelles
•Example: Human cells

Structure of a Human Cell

1. Cell Membrane

Function:

•Surrounds and protects the cell
•Controls movement of substances in and out of the cell
•Maintains cell shape

Important Point:

The cell membrane is selectively permeable.

2. Cytoplasm

Function:

•Jelly-like substance inside the cell
•Holds organelles in place
•Site of many chemical reactions

, 3. Nucleus

Function:

•Control center of the cell
•Contains genetic material (DNA)
•Regulates cell activities and reproduction

Important Point:

•The nucleus is surrounded by the nuclear membrane.

Cell Organelles and Their Functions

1. Mitochondria

Function:

•Produce energy (ATP)
•Known as the powerhouse of the cell

2. Ribosomes

Function:

•Site of protein synthesis
•Can be free or attached to rough ER

3. Endoplasmic Reticulum (ER)

Rough ER

•Contains ribosomes
•Helps in protein synthesis and transport

Smooth ER

•Lacks ribosomes
•Helps in lipid synthesis and detoxification

4. Golgi Apparatus

Function:
•Modifies and packages proteins