3. History
• The study of cells started about three
hundred years ago.
• With the help of one powerful instrument
the cell was begin to be known to humans.
4. Cell Discovery
• The scientist who have contributed to
the discovery of the cell:
Hans and Zacharias Jansen
Robert Hooke
Matthias Schleiden
Theodor Schwann
Robert Brown
11. 1674
.
• Anton van Leeuwenhoek
Dutch Businessman.
Described cells in a drop of pond water that he
called “animalcules”
“Father of Ancient
Microbiology”
16. 1858
• Rudolph Virchow
Completed the cell theory by expounding
his famous conclusion “omnis cellula e
cellula” or cells develop from pre- existing
cells.
17. Cell Theory According to Schwann
1) The cell is the unit of structure,
physiology, and organization in living
things.
2) The cell retains a dual existence as
a distinct entity and a building block
in the construction of organisms.
18. Continued…
3) Cells form by free-cell formation,
similar to the formation of crystals
(spontaneous generation).
21. Revised Cell Theory
1. All known living things are made up of cells.
2. The cell is structural & functional unit of all living
things.
3. All cells come from pre-existing cells by division.
(Spontaneous Generation does not occur).
23. LEARNING OBJECTIVES
• To understand basic science CELL
BIOLOGY
• Comprehend the way in which molecules
of a cell cooperate to create a system
that feeds, moves, grows, divides and
respond to stimuli
• Be acquainted with the core concepts of
cell biology in considerable depth
24. 14
BIOLOGY?
Biology (from Greek βιολογία - βίος, bios, "life"; -λογία, -logia, study of) is
the science that studies living organisms
Living things
structure
function
origin
evolution
distribution
classification
principles
Cell theory
Evolution
Genes
Homeostasis
Energy
Microbiology
Molecular
biology
biochemistry
Zoology
Botany
Cellular
biology
Cell physiology
Ecology
25. 15
CELL BIOLOGY?
• Cell biology (formerly cytology, from the
Greek kytos, "container").
Cell properties/ physiology
Structure
Organelles
Interaction with the
environments
27. 18
The cell is the structural unit of life.
All organism is make up of cells.
28. 1.1 The Discovery of Cells (1)
• The discovery of cells
followed form the invention
of the microscope by Robert
Hooke, and its refinement by
Anton Leewenhoek.
29. The Discovery of Cells
• Cell theory was articulated in the mid-1800s
by Schleiden, Schwann and Virchow.
– All organisms are composed or one or more cell.
– The cell is the structural unit of life.
– Cells arise from pre-existing cells by division.
30. Basic Properties of Cells
• Life is the most basic
property of cells.
• Cells can grow and
reproduce in culture for
extended periods.
– HeLa cells are cultured
tumor cells isolated form
a cancer patient
(Henrietta Lacks) by
George Gey in 1951.
– Cultured cells are an
essential tool for cell
biologists.
31. Basic Properties of Cells
• Cells Are Highly Complex and
Organized
–Cellular processes are highly regulated.
–Cells from different species share similar
structure, composition and metabolic
features that have been conserved
throughout evolution.
33. Basic Properties of Cells
• Cells Posses a Genetic Program and
the Means to Use It
–Genes encode information to build
each cell, ad the organism.
–Genes encode information
for cellular reproduction,
activity, and structure.
35. Basic Properties of Cells (4)
• Cells Are Capable
of Producing
More of
Themselves
– Cells reproduce, and
each daughter cells
receives a complete
set of genetic
instructions.
36. Basic Properties of Cells
• Cells Acquire and Utilize Energy
– Photosynthesis provides fuel for all living
organisms.
– Animal cells derive energy from the products of
photosynthesis, mainly in the form of glucose.
– Cell can convert glucose into ATP—a substance
with readily available energy.
37. Basic Properties of Cells
• Cells Acquire and Utilize
Energy
• Cells Carry Out a Variety
of Chemical Reactions
• Cells Engage in
Mechanical Activities
• Cells Are Able to
Respond to Stimuli
38. Basic Properties of Cells
• Cells Are
Capable of
Self-Regulation
• Cells Evolve
39. Two Fundamentally Different Classes
of Cells
• Prokaryotic and
eukaryotic are
distinguished by their
size and type of
organelles.
• Prokaryotes are all
bacteria, which arose
~3.7 billion years ago.
• Eukaryotes include
protists, animals, plan
ts and fungi.
42. Basic Properties of Cells (2)
• Characteristics that distinguish prokaryotic
and eukaryotic cells
– Complexity: Prokaryotes are relatively
simple; eukaryotes are more complex in
structure and function.
– Genetic material:
• Packaging: Prokaryotes have a nucleoid region whereas
eukaryotes have a membrane-bound nucleus.
• Amount: Eukaryotes have much more genetic material
than prokaryotes.
• Form: Eukaryotes have many chromosomes made of
both DNA and protein whereas prokaryotes have a
single, circular DNA.
46. Basic Properties of Cells
• Characteristics that distinguish prokaryotes and
eukaryotes
– Cytoplasm: Eukaryotes have membrane-bound
organelles ad complex cytoskeletal proteins. Both
have ribosomes but they differ in size.
– Cellular reproduction: Eukaryotes divide by mitosis;
prokaryotes divide by simple fission.
– Locomotion: Eukaryotes use both cytoplasmic
movement, and cilia and flagella; prokaryotes have
flagella, but they differ in both form and mechanism.
51. Basic Properties of Cells
• Prokaryotic Diversity
– Prokaryotes are identified and classified on the basis of
specific DNA sequences.
– Recent evidence indicates that prokaryotes are more
diverse and numerous than previous thought.
52. Basic Properties of Cells (6)
• Types of Eukaryotic Cells: Cell Specialization
–Unicellular eukaryotes are complex single-
celled organisms.
–Multicellular eukaryotes have different cell
types for different functions.
• Differentiation occurs during embryonic
development
in other multicellular organisms.
• Numbers and arrangements of organelles relate to
the function of the cell.
• Despite differentiation, cells have many features in
common.
53. Basic Properties of Cells
• Multicellular eukaryotes have different
cell types for different functions.
–Model Organisms:
• Cell research focuses on six model organisms.
• These are the bacterium Escherichia coli, the
yeast Saccharomyces, the mustard plant
Arabidopsis, the nematode Caenorhabditis
elegans, the fruit fly Drosophila, and the mouse
Mus musculus.
55. The Human Perspective: The Prospect of
Cell Replacement Therapy (1)
• Stem cells are undifferentiated cells
capable of self-renewal and
differentiation.
–Adult stem cells can be used to replace
damaged or diseased adult tissue.
• Hematopoietic stem cells can produce blood
cells in
bone marrow.
• Neural stem cells may be sued to
treat neurodegenerative disorders.
57. The Human Perspective: The Prospect of
Cell Replacement Therapy (2)
• Embryonic stem (ES) cells have even
greater potential for differentiation
(pluripotent) than adult stem cells.
–ES cells must be differentiated in vitro.
–The use of ES cells involves ethical
considerations.
58. A procedure for obtaining differentiated cells
for use in cell replacement therapy
59. Steps taken to generate iPS for use in correcting
the inherited disease sickle cell anemia in mice
60. Basic Properties of Cells (8)
• The Sizes of Cells and Their Components
– Cells are commonly measured in units of
micrometers (1 μm = 10–6 meter) and nanometers
(1 nm = 10–9 meter).
– Cell size is limited:
• By the volume of cytoplasm that can be supported by
the genes in the nucleus.
• By the volume of cytoplasm that can be supported
by exchange of nutrients.
• By the distance over which substances can efficiently
travel through the cytoplasm via diffusion.
62. Basic Properties of Cells
• Synthetic Biology is a field oriented to create
a living cell in the laboratory.
– A more modest goal is to develop novel life
forms, beginning with existing organisms.
– Possible applications to medicine, industry, or the
environment.
– Prospect is good after replacing the genome of
one bacterium with that of a closely related
species.
64. Think Back to Last
Class
A cell is the basic structural and functional unit of all
living things
Eukaryotic & Prokaryotic
Animal & Plant
How cells fit into the rest of the body’s organization
Cell Tissu
e
Organ System
Organ
Organism
65. Cell Membrane
Provides support and protection
Functions as cell
Think of our school’s doors and intercom
system
and
66. Cytoplasm
Jelly-like material that fills the cell
Contains water and food for cell
Holds organelles in place
Think of the air that fills up this entire school
67. Nucleus
Contains DNA, which makes you who you are
Directs the activity of the cell – for example,
when it growsand d i v i d e s
Think of the principal’s office as the nucleus and the
student files in the office as DNA
68. Endoplasmic Reticulum
(E.R.)
The “highway” of the cell that moves materials
around to other parts
Some parts of the E.R. contain ribosomes, which
create proteins
Think of the school hallways where students and
teachers transport ideas to other parts of the school
If you drive
too fast,
you’ll end up
in the E.R.!
69. Golgi Apparatus
Packages, stores, and secretes energy
for the cell
Think of the lunch faculty who bring
cafeteria food into the school, then
pack and store it in the kitchen for
later use
70. Mitochondria
Break down food and release energy to
cell – the “Powerhouse” of the cell
Think of lunch time at school – food is
taken out of packages, cooked, and then
provided to students and teachers to
power them for the rest of the day
71. Lysosome
s
Clean up the cell waste products
(Lysosomes clean just like Lysol!)
Think of the janitors who clean up any
waste in the school at the end of the day
74. Why are there Organelles?
• Specialized Functions
• Act as containers (separate parts of the
cell from other parts)
• Sites for chemical reactions (ex.
Chloroplasts and Mitochondria)
75. Nucleus
• Control Center of the
cell
• Contains DNA and
RNA
• Large, roundish
organelle
• Can produce Proteins
City Hall/ Mayor’s Office
76. Endoplasmic Reticulum (ER)
• Folded membrane that
extends through the
cytoplasm to the nuclear
membrane
• 2 Kinds:
– Rough- Has ribosomes
attached and is involved with
protein transport
– Smooth- Lacks ribosomes and
is involved with detoxification of
poison and lipid synthesis
http://publications.nigms.nih.gov/insidethecell/images/ch1_roughER.jpg
77. Ribosomes
• Dot-like structures produced in the
nucleus
• Site of protein synthesis
• Each ribosome is composed of 2 sub-
units: small and large
• 2 type of ribosomes:
– Free: floating in the cytoplasm
– Attached: associated with the ER
Protein Factory
78. Golgi Apparatus
• Stacks of sacs with
vesicles pinching off
from the edges
• Packages materials for
export from the cell
• Will modify lipids and
proteins
• Stores and packages
materials for export out
of cell
http://www.sciencenews.org/view/download/id/48467/name/Golgi_apparatus
Post Office
79. Mitochondria
• Primary energy
producers of cells
• Double membrane
• Produces ATP via
aerobic respiration
• Have their own DNA
and method of
replication
• Endosymbiotic
Theory
Power Plant
http://shs.westport.k12.ct.us/asr/Bio%202/webquests/cell%20city/organelle%20links/mitochondria.gif
80. Chloroplasts
• Site of photosynthesis
• Chlorophyll = Green Color
• Endosymbiotic Theory
QuickTimeªand a
decompressor
are neededto see thispicture.
http://www.cbs.dtu.dk/staff/dave/roanoke/chloroplast.gif
81. Microtubules
• Made from proteins within eukaryotic
cells
• Provide the structure for the cell-
cytoskeleton
• Tracks for transporting organelles &
vesicles
• Pull apart chromosomes during division
• Ex: Cillia and flagella
82. Centrioles
• Found in eukaryotic cells
• Come in pairs
• Made from short microtubules
• Assist the cell with cell division
83. Vacuoles
• Single membranes that
surround solid or liquid
contents
• Vacuole will as a
container for the cell
• Plant cells usually have
1 large vesicle filled
with water
• 50-90% of a plant cell’s
volume is a vacuole
Storage Unit
http://education.kings.edu/dsmith/vacuole.jpg
84. Vesicles
• Sac surrounded by a single membrane
• Endocytotic- will bring contents into cell
• Exocytotic- takes materials out of cell
UPS/Delivery Service
85. Lysosomes
• Sacs within the cell that contains
digestive enzymes
• Encased within a single membrane
• Used to digest/breakdown complex
organic molecules
• Lysosome will merge with the “food” &
the contents will begin the digestion
Dump or Garbage Truck
86. Peroxisomes
• Resemble Lysosomes with structure
and function
• Sac with a single membrane that break
down amino acids, alcohol and fatty
acids
• Unique because it produces and
disposes of Hydrogen Peroxide, which
is fatal to cells
87. Cell Wall
• Thin layer of
cellulose that
surrounds the cell
• Permeable to many
substances
• Provides strength
and support to the
plant
http://www.desmids.nl/info/sheddingoftheprimarycellwall/images/Pleurotaeniumehrenbergii3.jpg
City Limit
88. Cell Membrane
• Semi-permeable membrane that lets some
things in and prevents materials from leaving
• Provides limited structure
• Lipid bilayer
http://wiki.chemprime.chemeddl.org/images/thumb/6/60/Lipid-Bilayer_Model_for_Membranes_.jpg/470px-Lipid-Bilayer_Model_for_Membranes_.jpg
City Limit
91. Sizes of Living Things
http://amazedatbio.wordpress.com/2012/09/17/life-is-cellular/
Minimum resolution of a LM 2 microns, the size of a small bacterium
LM can magnify effectively to 1,000 times the size of the actual specimen.
3
92. Properties of life
Reproduction :
o sexual : genetic variation, fertilization
o asexual : genetically identical, e.g. sporulation, budding,
regeneration, binary fission
Metabolism : anabolism Vs. catabolism
Growth and Development
Response to environment
Homeostasis : regulated via organ system
Organization : Cell, tissue, organ, organ system, organism
o acellular
o unicellular : bacteria, yeast
o multicellular : plant, animal
4
93. Cell Theory
All organisms are composed of cells
All cells come only from preexisting cells (Rudolf Virchow)
Cells are the smallest structural and functional unit of organisms
Cells carry genetic information in the form of DNA
5
Robert Hooke (1665) Matthias Jacob
Schleiden (1838)
plant
Theodor Schwann
(1839)
animal
Antony van
Leeuwenhoek (1673)
95. Electron microscope
To resolve smaller structures we use EM, which focuses a beam
of electrons through the specimen (TEM) or onto its surface
(SEM)
TEM are used to study the internal ultrastructure of cells.
A TEM aims an electron beam through a thin section of the
specimen.
o The image is focused and magnified by electromagnets.
o To enhance contrast, the thin sections are stained with
atoms of heavy metals.
SEM are useful for studying surface structures.
The SEM has great depth of field, resulting in an image that
seems three-dimensional.
7
97. Prokaryotic and eukaryotic cells
All cells
o surrounded by a plasma membrane.
o have cytosol, containing the organelles.
o containchromosomes
o haveribosomes
A major difference
o eukaryotic cell: chromosomes are contained in the
nucleus (within a membranous nuclear envelope)
o prokaryotic cell: the DNA is concentrated in the
nucleoid
9
98. A major difference...
Cytoplasm
o All the material within the plasma membrane of a prokaryotic
cell is cytoplasm.
o Within the cytoplasm of a eukaryotic cell is a variety of
membrane-bounded organelles of specialized form and
function.
Eukaryotic cells are generally much bigger than prokaryotic
cells.
o smallest bacteria, mycoplasmas, are 0.1 to 1.0 micron. (most
bacteria: 1-10 microns)
o Eukaryotic cells are typically 10-100 microns in diameter
10
100. 12
Eukaryotic Cells Prokaryotic Cells
“complex” organisms, including all
plants, protists, fungi and animals
“Simple” organisms, including
bacteria and cyanobacteria
Contain nucleus and membrane bound
organelles
Several chromosome
Lack nucleus and other
membrane-encased organelles.
Single chromosome (DNA + non-
histone protein)
Can specialize for certain functions,
multicellular organs and organisms
Usually exist as single, virtually
identical cells
Cellular respiration occur in
mitochondria
Cellular respiration occur in
mesosome (extended membrane)
Ribosome: 40s, 60S Ribosome: 30S, 50S
Photosynthesis occur in chloroplast Photosynthesis occur in
chlorophyll located region
Cell Wall present in Plants & Fungi only Cell Wall
Cyanobacteria (blue-green algae) e.g. Nostoc,
101. Cells
Cell coat: Cell wall, Cell membrane
Protoplasm
o Nucleus : nuclear membrane, nucleoplasm (chromatin fiber,
nucleolus)
o Cytoplasm
• cytosol
• organelle
– no membrane bounded: ribosome, centriole,
cytoskeleton
– single membrane bounded: ER, Golgi complex,
lysosome, peroxisome, vacuole
– double membrane bounded: mitochondria, chloroplast
13
104. Plasma membrane
Fluid mosaic model
o Phospholipid bilayer acts
more like a fluid than a
liquid
Contains integral and
peripheral proteins
Semi permeable membrane
Like a city border they
surround the cell and are able
to regulate entrance and exit
16
Campbell et al, Biology; 2009.
105. Phospholipid bilayer
polar heads face outward towards the watery environments both inside and
outside the cell
non polar tails face inward away from the watery environment 17
http://alevelnotes.com/content_images/i38_phospholipid.gif
http://online.morainevalley.edu/WebSupported/BIO111-
Gibbons/membra29.jpg
108. Function of membrane protein
Chandar et al, Lippincott’s Illustrated Reviews: Cell and Molecular Biology; 2010.
Enzyme
Mediate the passage of ions and most biological molecule
Selective traffic of molecule
Control the interactions between cells of multicellular organisms
Serve as sensor (e.g. receptors, signal transductions)
20
109. Transport through membrane
Passive transport: need no energy, downhill
o simplediffusion
o facilitated diffusion: channel protein, carrier protein
Active transport: need energy, uphill
o primary active : direct hydrolysis of ATP
o secondary active : symporters, antiporters
Vesicle transport
o endocytosis: receptor mediated, phagocytosis,
pinocytosis
o exocytosis
21