Cell Biology and Physiology Notes
Cell Biology
Definition: Study of cells, their structure, function, and behavior.
Significance: Cells are the basic units of life, and understanding them is crucial for biology
and medicine.
Types of Cells
1. Prokaryotic Cells
- No membrane-bound nucleus.
- DNA is circular and located in the nucleoid.
- Examples: Bacteria and Archaea.
2. Eukaryotic Cells
- Membrane-bound nucleus.
- Contain organelles like mitochondria and the endoplasmic reticulum.
- Examples: Plants, animals, fungi, and protists.
Cell Theory
1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of life.
3. All cells arise from pre-existing cells.
Cell Structure and Functions
Plasma Membrane
Semi-permeable barrier. Composed of a phospholipid bilayer with embedded proteins.
Functions: Protection, communication, and transport.
Cytoplasm
Jelly-like substance containing organelles. Site of most cellular activities.
Nucleus
Contains genetic material (DNA). Controls cellular functions and reproduction.
Mitochondria
Known as the powerhouse of the cell. Produces energy (ATP) through cellular respiration.
Endoplasmic Reticulum (ER)
Smooth ER: Synthesizes lipids and detoxifies chemicals. Rough ER: Studded with
ribosomes; involved in protein synthesis.
Cell Biology
Definition: Study of cells, their structure, function, and behavior.
Significance: Cells are the basic units of life, and understanding them is crucial for biology
and medicine.
Types of Cells
1. Prokaryotic Cells
- No membrane-bound nucleus.
- DNA is circular and located in the nucleoid.
- Examples: Bacteria and Archaea.
2. Eukaryotic Cells
- Membrane-bound nucleus.
- Contain organelles like mitochondria and the endoplasmic reticulum.
- Examples: Plants, animals, fungi, and protists.
Cell Theory
1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of life.
3. All cells arise from pre-existing cells.
Cell Structure and Functions
Plasma Membrane
Semi-permeable barrier. Composed of a phospholipid bilayer with embedded proteins.
Functions: Protection, communication, and transport.
Cytoplasm
Jelly-like substance containing organelles. Site of most cellular activities.
Nucleus
Contains genetic material (DNA). Controls cellular functions and reproduction.
Mitochondria
Known as the powerhouse of the cell. Produces energy (ATP) through cellular respiration.
Endoplasmic Reticulum (ER)
Smooth ER: Synthesizes lipids and detoxifies chemicals. Rough ER: Studded with
ribosomes; involved in protein synthesis.
