Cell and Molecular Biology
Intended learning outcomes: After completing the course the students will be able to
1. List the cell organelles found in prokaryotes, eukaryotes and archaea and identify the
specific functions each organelle
2. Describe the cell cycle and explain how each stage is regulated under different
3. Explain the central dogma of molecular biology and describe each step how these steps
affect on gene expression
4. Describe the process of cancer development and the genes involved in the process
5. Discuss how signal transduction takes place in animal cells
6. Describe different cellular movements, cytoskeletal systems, cell adhesions, cell
junctions and extracellular structures found in animal and plant cells
What is a cell?
• an autonomous biological unit
• smallest living unit
• Individual cells can:
• grow, reproduce, process information, respond to stimuli, communicate, carry out
• carry hereditary material
• surrounded by a plasma membrane
• The Cell Theory states that:
1. All organisms are made up of one or more cells that all cells come from pre-
2. Vital functions of an organism occur within cells.
3. All cells contain hereditary information necessary for regulating cell functions
4. Hereditary information transmit information to the next generation of cells.
Types of cells
• Some cells are visible to the unaided eye
• The smallest object the human eye can see is 0.1mm long.
• Example :Ameoba proteus, a human egg, and a paramecium Single cell organisms—multi cell organisms
Single cell organisms -> microorganisms
Multi cell organisms -> higher degree or organization of cell within an organism->
specialization of cells
All Organisms are Bacteria,Archaea, or Eukaryotes
Biologists recognize two types of cells, 1. The simpler type, characteristic of bacteria:
a. Prokaryotes are single-celled organisms that are the earliest and most primitive
forms of life on earth.
b. It is organized into Three Domain System, prokaryotes include bacteria and
c. Prokaryotes are able to live and thrive in various types of environments including
extreme habitats such as hydrothermal vents, hot springs, swamps, wetlands, and
the guts of animals.
d. Prokaryotic cells are not as complex as eukaryotic cells.
e. They have no true nucleus as the DNAis not contained within a membrane or
separated from the rest of the cell, but it is coiled up in a region of the cytoplasm
called the nucleoid.
The more complex type of characteristic of plants, animals, fungi, algae, and protozoa:
a. Eukaryotes are organisms made up of cells that possess a membrane-bound
nucleus (that holds genetic material) as well as membrane-bound organelles.
b. Genetic material in eukaryotes is contained within a nucleus within the cell and
DNAis organized into chromosomes.
c. Eukaryotic organisms may be multicellular or single-celled organisms.
d. All animals are eukaryotes. Other eukaryotes include plants, fungi, and protists.
Changing View of prokaryotes:
• divergent bacteria and archaeas, prokaryotic cells can be divided into the widely Three types of RNA
rRNAor Ribosomal RNA
o rRNAis located in the cytoplasm of a cell, where ribosome’s are found. rR