Cell biology by Dr. Kshirsagar R.V

1. f.y.b.sc.
PAPER II-FIRST TERM
ZY 102:
FUNDAMENTALS OF CELL BIOLOGY
Dr.Ravindra Kshirsagar
M.Sc. Ph.D. F.G.S.B.A.S
Modern College,Ganeshkhind,Pune

2. SYLLABUS
PAPER II-FIRST TERM ZY 102:
FUNDAMENTALS OF CELL BIOLOGY
 1. Introduction to cell biology:
 1.1 Definition and scope
 1.2 Stains: Principle and composition of
vital stains, cytoplasmic stains and nuclear
stains with two examples of each
 2. Structure of prokaryotic (E.coli) and
eukaryotic (Plant and Animal) cell
3.Structure and function of cell membrane:
3.1 Chemical composition
 3.2 Fluid mosaic model
 3.3 Functions of plasma membrane
 4. Composition of Cytoplasm 1 5. Study of
following cell organelles with respect to
structure and functions in brief:
 5.1 Endoplasmic reticulum 5.2 Golgi
complex 5.3 Lysosomes, peroxisomes and
glyoxysomes 5.4 Ribosomes 5.5
Mitochondria
 6. Nucleus: 6.1 Shape, size, number and
position 6.2 Ultrastructure of nuclear
envelope and pore complex .3 Functions
 7. Cell division and their significance:
 7.1 Cell cycle in brief
 7.2 Mitosis 7.3 Meiosis

3. The cell is the basic structural, functional,
and biological unit of all known living
organisms.
A cell is the smallest unit of life that can replicate independently,
cells are often called the "building blocks of life“
.
The study of cells is called cell biology or cytology.

4. Animal and Plant Cells
Plant cells
are similar to animal cells in being eukaryotic and they have similar cell
organelles.
plant cells are larger than animal cells and are mostly similar in size and are
rectangular or cube shaped.
 Plant cell contains a few distinctive features like a cell wall, large vacuole and
plastids.
Animal cells
are typical eukaryotic cells. They are enclosed by plasma membrane and
constitutes of membrane bound nucleus and organelles. Animal cells do not have
cell wall.
 Due to the lack of the cell wall the size of the cell varies and the shape is
irregular.
 Animal cells contain structures like centrioles, cilia and flagella and lysosomes.

5.  Cell membrane: It is the outer lining of the cell
which encloses all other cell organelles. The cell
membrane also known as the plasma membrane is
semipermeable. It allows only specific molecules to
pass through and blocking others.
 Cell wall: The cell wall is a rigid layer that
surrounds the plant cells. Plant cell walls are
primarily made up of cellulose. It is located outside
the cell membrane whose main function is to
provide rigidity, strength, protection against
mechanical stress and infection.
 Cytoplasm: It is the fluid substance that fills the
cell. All the cell organelles are suspended in the
cytoplasm. The cytoplasm maintains the osmotic
concentration of the cells and prevents them from
bursting or shrinking.

 Nucleoplasm: It is the semi-fluid substance inside the nucleus,
contains the genetic material and the nucleolus.

 Mitochondria: Mitochondria is one of the largest organ of the cell
and is known as the 'power house of the cell'. It is a spherical or rod
shaped organelles and is enveloped by a double membrane. The
mitochondria aids in conversion of glucose to high energy molecules
(ATP) for the cell.

 Ribosomes: Ribosomes are found on the endoplasmic reticulum.
Together they help in manufacturing proteins for the cell following
instructions of the nucleus.

 Lysosomes: Lysosomes are membrane bound organelles, they
contain digestive enzymes. They break down the waste products
and detoxify the cell.

 Centrosome: It is a small body located near the nucleus. Centrioles
are made in the centrosomes. During cell division the centromere
organizes the assembly of the micro-tubules.

6.  Golgi apparatus: They are flattened
stacks of membrane bound sacs. They
function as the packaging unit, the
proteins formed by the endoplasmic
reticulum are packed into small
membrane sacs called vesicles.
 Vacuoles: They are organelles for
storage. Small membrane bound
vacuoles filled with fluids and water are
present in animals. In plant cells the
vacuoles perform functions of secretion,
excretion and storage.
 Chloroplasts: It is an elongated or disc-
shaped organelle containing chlorophyll.
It is the site for photosynthesis in a plant
cell. The green pigment chlorophyll
absorbs energy from sunlight.

 Endoplasmic reticulum: It is a large
network of interconnecting membrane
tunnels. It is composed of both rough
endoplasmic reticulum and smooth
endoplasmic reticulum. The rough
endoplasmic reticulum is covered with
ribosomes hence appears rough.
 They follow the instructions from the
nucleus and make proteins the cell needs.
 The smooth endoplasmic reticulum is
continuous with the outer nuclear
membrane. It transports material through
the cell and produces and digests lipids and
membrane proteins.

7. Nucleus:
It is a membrane bound organelle, spherical in shape. Most of the activities of
the cell is directed by the nucleus.
All the cells in an animal has one complete set of genes in its nucleus. The
genetic material DNA help in protein formation.
Nucleolus:
It is darkly stained are in the nucleus, it aids in protein formation and RNA
synthesis.
Nuclear membrane:
It is the porous double membrane layer surrounding the nucleus. It allows
passage of substances and is a distinctive characteristic of the eukaryotic cell.
Nucleoplasm:
It is the semi-fluid substance inside the nucleus, contains the genetic material
and the nucleolus.

8. Cytoskeleton:
It is a network of fibers made up of micro-tubule and micro-
filament. They maintain the shape and gives support to the
cell.
Plasmodesmata:
They are microscopic channels which traverse the cell
walls of plant cells and enables transport and
communication between them.
Plastids:
Plastids are storage organelles. They store products like
starch for synthesis of fatty acids and terpenes

9. Prokaryotic cell Eukaryotic cell

10.  The common features of prokaryotic and eukaryotic cells are:
 DNA, the genetic material contained in one or more chromosomes and
located in a nonmembrane bound nucleoid region in prokaryotes and a
membrane-bound nucleus in eukaryotes
 Plasma membrane, a phospholipid bilayer with proteins that separates
the cell from the surrounding environment and functions as a selective
barrier for the import and export of materials
 Cytoplasm, the rest of the material of the cell within the plasma
membrane, excluding the nucleoid region or nucleus, that consists of a
fluid portion called the cytosol and the organelles and other
particulates suspended in it
 Ribosomes, the organelles on which protein synthesis takes place

11. I DON’T DO DIFFERENT THINGS
I DO THINGS DIFFERENTLY