Cell Structure Study Guide | High School
Biology | Key Terms, Functions & Exam
Prep
1. What is a Cell?
A cell is the smallest unit of life. All living organisms are made of one or more cells. Cells
perform the basic functions needed for life, such as producing energy, growing, and
reproducing.
Cells contain different structures called organelles, which carry out specific jobs inside the cell.
2. Two Main Types of Cells
Prokaryotic Cells
Prokaryotic cells are simple cells that do not have a nucleus.
Characteristics:
● Usually very small
● DNA floats freely inside the cell
● Do not contain membrane-bound organelles
Example: bacteria
Eukaryotic Cells
Eukaryotic cells are more complex cells that contain a nucleus.
Characteristics:
, ● Larger than prokaryotic cells
● Contain many organelles
● DNA is stored inside the nucleus
Examples:
● Animal cells
● Plant cells
3. Important Cell Organelles
Cell Membrane
The cell membrane surrounds the cell and controls what enters and leaves the cell.
Functions:
● Protects the cell
● Maintains balance inside the cell
● Allows certain materials to pass through
Nucleus
The nucleus acts as the control center of the cell.
Functions:
● Stores DNA
● Controls cell activities
● Directs protein production
Cytoplasm
The cytoplasm is the jelly-like fluid inside the cell where organelles are located.
Functions:
Biology | Key Terms, Functions & Exam
Prep
1. What is a Cell?
A cell is the smallest unit of life. All living organisms are made of one or more cells. Cells
perform the basic functions needed for life, such as producing energy, growing, and
reproducing.
Cells contain different structures called organelles, which carry out specific jobs inside the cell.
2. Two Main Types of Cells
Prokaryotic Cells
Prokaryotic cells are simple cells that do not have a nucleus.
Characteristics:
● Usually very small
● DNA floats freely inside the cell
● Do not contain membrane-bound organelles
Example: bacteria
Eukaryotic Cells
Eukaryotic cells are more complex cells that contain a nucleus.
Characteristics:
, ● Larger than prokaryotic cells
● Contain many organelles
● DNA is stored inside the nucleus
Examples:
● Animal cells
● Plant cells
3. Important Cell Organelles
Cell Membrane
The cell membrane surrounds the cell and controls what enters and leaves the cell.
Functions:
● Protects the cell
● Maintains balance inside the cell
● Allows certain materials to pass through
Nucleus
The nucleus acts as the control center of the cell.
Functions:
● Stores DNA
● Controls cell activities
● Directs protein production
Cytoplasm
The cytoplasm is the jelly-like fluid inside the cell where organelles are located.
Functions:
