1. Cell Structures
and Functions

2. The Cell
 the smallest unit of life
that can carry out all
the functions of a living
thing.
 fundamental building
blocks of organisms.

3. Brief History
of the Cell

4. Antonie van Leeuwenhoek
(1632-1723)

5. Robert Hooke (1635-1703)

6. Cork Cell
The word cell comes from the
Latin cella, a small room.

7. The Cell Theory
 Robert Brown (1831)
 Described the nucleus of the cell
 Matthias Schleiden (1838)
 All plants are composed of cells.
 Theodor Schwann (1838)
 All animals are composed of cells
 Rudolph Virchow (1850s)
 Cells reproduce

8. The Cell Theory
 All organisms are composed of
cells.
 Cells are the basic units of
structure and function in organisms.
 Cells come only from pre-existing
cells because cells are self-
reproducing.

9. Microscopy Today
 Electron
Microscopes are
scientific instruments
that use a beam of
highly energetic
electrons to examine
objects on a very
fine scale.

10. Sizes of Living Things
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
0.1 nm 1 nm 10 nm 100 nm 1 m 10 m 100 m 1 mm 1 cm 0.1 m 1 m 10 m 100 m 1 km
protein
chloroplast
plant and mouse rose
animal frog egg
amino cells
acid
virus
ostrich
most bacteria human egg ant egg
atom
blue whale
electron microscope human
light microscope
human eye
10

11. Microscopy Today
 Topography: shows the surface
features of an object or "how it looks",
its texture; and materials properties
(hardness, reflectivity...etc.)
 Morphology: shows shape and size of
the particles making up the object; and
materials properties (ductility, strength,
reactivity...etc.)

12. Animal Cell Anatomy
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Plasma membrane:
outer surface that
regulates entrance and
exit of molecules
protein
phospholipid Nucleus: command center of cell
Nuclear envelope: double
Cytoskeleton: maintains membrane with nuclear pores
cell shape and assists movement that encloses nucleus
of cell parts: Chromatin: diffuse threads
containing DNA and protein
Microtubules: protein Nucleolus: region that produces
cylinders that move subunits of ribosomes
organelles
Endoplasmic reticulum:
Intermediate filaments: protein and lipid metabolism
protein fibers that provide Rough ER: studded with
stability of shape ribosomes that synthesize
Actin filaments: protein proteins
fibers that play a role in Smooth ER: lacks
change of shape ribosomes, synthesizes
lipid molecules
Centrioles*: short Peroxisome: vesicle
cylinders of microtubules that is involved in
of unknown function fatty acid metabolism
Centrosome: microtubule Ribosomes:
organizing center that particles that carry
contains a pair of centrioles out protein synthesis
Lysosome*: vesicle that Polyribosome: string of
digests macromolecules ribosomes simultaneously
and even cell parts synthesizing same protein
Vesicle: small membrane-
bounded sac that stores
and transports substances
Mitochondrion: organelle
Cytoplasm: semifluid that carries out cellular
matrix outside nucleus respiration, producing ATP
that contains organelles molecules
Golgi apparatus: processes, packages,
*not in plant cells and secretes modified proteins
12

13. Microscopy and Cheek Cells
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
30 m 30 m 25 m 25 m 25 m
Bright-field. Light Bright-field (stained). Differential interference Phase contrast. Density Dark-field. Light is passed
passing through the Dyes are used to stain contrast. Optical methods differences in the through the specimen at
specimen is brought the specimen. Certain are used to enhance specimen cause light rays an oblique angle so that
directly into focus. Usually, components take up density differences within to come out of “phase.” the objective lens receives
the low level of contrast the dye more than other the specimen so that The microscope enhances only light diffracted and
within the specimen components, and therefore certain regions appear these phase differences so scattered by the object.
interferes with viewing all contrast is enhanced. brighter than others. This that some regions of the This technique is used to
but its largest components. technique is used to view specimen appear brighter view organelles, which
living cells, chromosomes, or darker than others. The appear quite bright against
and organelle masses. technique is widely used a dark field.
to observe living cells and
organelles.
(Bright field): © Ed Reschke; (Bright field stained): © Biophoto Associates/Photo Researchers, Inc.;
(Differential, Phase contrast, Dark field): © David M. Phillips/Visuals Unlimited
13

15. Two Basic Types
of Cell Structure
 Prokaryotic
 Eukaryotic

16. Two Basic Types
of Cell Structure
 Prokaryotic
 “pro” = before, “kary”= nut (nucleus)
 NO nucleus or NO organelles
 Genetic material (DNA) is naked in
the cytoplasm
 Cell division is called binary fission

17. Two Basic Types
of Cell Structure
 Prokaryotic
 Believed to be
the first cells
to evolve.
 Ribosomes
are the only
organelle.

18. Binary Fission:
Prokaryotes Cell Division

19. Two Basic Types
of Cell Structure
Prokaryotic
• Kingdom Monera
• Kingdom Archaea

20. Two Basic Types
of Cell Structure
 Prokaryotic
 Eukaryotic

21. Two Basic Types
of Cell Structure
Eukaryotic
 Nucleus containing DNA
 “Eu” - true
 Organelles (membrane bound)
with specialized functions
 Cell division: mitosis and meiosis

22. Two Basic Types
of Cell Structure
Eukaryotic
• Kingdom Protista
• Kingdom Fungi
• Kingdom Plantae
• Kingdom Animalia

23. Differences between Prokaryotic & Eukaryotic cells
Bacterial cells also contain flagellum, plasmid and capsule.
Feature Prokaryote Eukaryote
Size Small about 0.5 Up to 40 micrometers
micrometers
Genetic Circular DNA (in DNA in form of linear
material cytoplasm) chromosomes ( in nucleus)
Many organelles:
Few present, none •Double membranes e.g.:
Organelles nucleus, mitochondria &
membrane bound
chloroplasts
•Single membrane e.g.: GA,
ER & lysosomes
•Fungi: rigid, formed from
Rigid formed from polysaccharide, chitin.
Cell walls glycoproteins (mainly •Plant: rigid, formed from
polysaccharides. E.g.:
murein)
cellulose.
•Animals no cell wall
Ribosome’s 70s 80s

24. VIDEO

26. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolu
Nucleu s
Cell Membrane
s
Go to
Section:

27. Eukaryotic Cell Organelles and
Function
1. Nucleus
 Nickname: “The Control Center”
 Function: holds the DNA
 Parts:
1. Nucleolus: dark spot in the
middle of the nucleus that helps
make ribosomes

28. Eukaryotic Cell Organelles and
Function

30. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolus
Ribosome
Nucleus
s Cell Membrane
Go to
Section:

31. Eukaryotic Cell Organelles and
Function
2. Ribosomes
 Function: makes proteins
 Found in all cells, prokaryotic
and eukaryotic

32. Eukaryotic Cell Organelles and
Function
3. Endoplasmic Reticulum
(ER)
 Nickname: “Roads”
 Function: The internal
delivery system of the cell

33. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolus Ribosomes
Nucleus Cell Membrane
Smooth
Rough Endoplasm
Endoplasmi ic
c Reticulum
Reticulum
Go to
Section:

34. Endoplasmic Reticulum
 Rough ER:
Rough appearance
because of ribosomes
 Function: helps make
proteins, that’s why it
has ribosomes

35. Endoplasmic Reticulum
Smooth ER:
• similar in appearance with RER but NO
ribosomes
•Function: functions depending on the
specific cell type including lipid and
steroid hormone synthesis ,
breakdown of lipid-soluble toxins in
liver cells, and control of calcium
release in muscle cell contraction.

36. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolus Ribosomes
Nucleus Cell Membrane
Smooth Endoplasmic
Rough Endoplasmic Reticulum
Reticulum
Golgi
Complex
Go to
Section:

37. Eukaryotic Cell Organelles and
Function
4. Golgi Complex
 Nickname: The shippers
 Function: packages, modifies,
and transports materials to
different location inside/outside
of the cell
 Appearance: stack of pancakes

38. Eukaryotic Cell Organelles and
Function
Golgi Complex
Modifies proteins
and lipids made
by the ER and
prepares them
for export from
the cell

39. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolus Ribosomes
Nucleus Cell Membrane
Smooth Endoplasmic
Rough Endoplasmic Reticulum
Reticulum
Golgi Bodies
Go to
Section:

40. Eukaryotic Cell Organelles and
Function
5. Lysosomes: circular, but bigger
than ribosomes
 Nickname: “Clean-up Crews”
 Function: to break down food
into particles the rest of the cell
can use and to destroy old cells

41. Eukaryotic Cell Organelles and
Function
 Single membrane
bound structure.
 Contains digestive
enzymes that break
down cellular waste
and debris and
nutrients for use by
the cell.
 Http://micro.magnet.fsu.edu/cells/animals/lysoso
me/html

42. Animation

43. Figure 7-5 Plant and Animal Cells
Section 7-2 Animal Cell
Cytoplasm
Nucleolus Ribosomes
Nucleus Cell Membrane
Mitochondri
Rough Endoplasmic a Smooth Endoplasmic
Reticulum
Reticulum
Golgi Bodies

45. Eukaryotic Cell Organelles and
Function
6. Mitochondria
 Nickname: “The Powerhouse”
 Function: Energy formation
 Breaks down food to make ATP
 ATP: is the major fuel for all
cell activities that require
energy

46. Animal Cell
Cytoplasm
Nucleolus Ribosomes
Nucleus Cell Membrane
Mitochondria
Rough Endoplasmic Smooth Endoplasmic
Reticulum Reticulum
Golgi Bodies

47. Eukaryotic Cell Organelles and
Function
7. Plasma Membrane
• Another name: Cell Membrane;
“traffic enforcer”
• Function: hold the cell together. It
keeps all of the pieces, like the
organelles and the CYTOPLASM
inside; regulates the entrance and
exit of materials in and out the cell.

48. Plasma
Membrane
Fluid Mosaic Model of Plasma Membrane

50. Fluid Mosaic Model of the Plasma
Membrane
The membrane is seen as a bilayer of phospholipids
in which protein molecules are embedded.
Lipid bilayer
a. Phospholipids : polar head and nonpolar tail
b. Cholesterol: makes membrane a bit more rigid
c. Proteins: provide means of transportation
through membrane and receptor proteins
d. Carbohydrates: recognition patterns for cells
and organisms (“self” markers to avoid immune
system attack)

51. 8. Cytoskeleton
-composed of
filaments and
microtubules
that maintain the
cell shape and
assist movement
of its part

52. Eukaryotic Cell Organelles and
Function
9. Cilia and flagella
 External
appendages from
the cell membrane
that aid in
locomotion of the
cell.
 Cilia also help to
move substance
past the membrane.

53. Cilia and Flagella
• The most common
examples of ciliated cells
are those that line the
trachea, or wind pipe of
animals.
• The cilia move mucus
containing dirt and other
inhaled particles up the
windpipe and into the
esophagus where they can
be coughed up or

54. Cilia and Flagella
Paramecium sp.
This unicellular organism sweeps food into its
mouth by using cilia.

55. Cilia and Flagella
Sperm cell has a tail or "flagellum"
which executes the lashing
movements to propel the sperm.

56. Eukaryotic Cell Organelles and
Function
10. Centrioles  Found only in animal
cells.
 Self-replicating
 Made of bundles of
microtubules.
 Help in organizing
cell division.

57. 11. Cytosol/Cytoplasm
• The cytosol is the "soup"
within which all the other cell
organelles reside and where most
of the cellular metabolism occurs .
* Though mostly water, the cytosol is full
of proteins that control cell metabolism
including signal transduction pathways,
glycolysis, and transcription factors.

58.  Structures only
found in
PLANT Cells

59. Plant Cell
Figure 7-5 Plant and Animal Cells
Section 7-2
Vacuole
Cell Membrane
Go to
Section:

60. Eukaryotic Cell Organelles and
Function
11. Huge vacuoles
 Function: store water, waste
products, food, and other cellular
materials.
 It may take up most of the cell's
volume.
 When there is no water, the
plant wilts

62. Eukaryotic Cell Organelles and
Function

63. Plant Cell
Figure 7-5 Plant and Animal Cells
Section 7-2
Vacuole
Chloroplast
sCell Membrane
Go to
Section:

64. Eukaryotic Cell Organelles and
Function
12. Chloroplasts
 Function: traps energy from the
sun to produce food for the plant
cell
 Green in color because of
chlorophyll

65. Chloroplasts

66. Plant Cell
Figure 7-5 Plant and Animal Cells
Section 7-2
Vacuole
Chloroplasts
Cell Membrane
Cell
Wall
Go to
Section:

67. Eukaryotic Cell Organelles and
Function
9. Cell Wall
 Function: provides support and
protection to the cell membrane;
gives rigidity to the cell
structure.
 Found outside the cell
membrane in plant cells.

68. Eukaryotic Cell Organelles and
Function

69. Plant Cell
Cytoplasm
Vacuole Smooth ER
Ribosomes
Chloroplasts
Cell Membrane
Cell Wall
Nucleolus
Golgi Bodies
Nucleus
Mitochondria
Rough ER

70. Cell Structure Reflects Cell
Function
 Muscle cells: contain numerous
mitochondria providing energy needed
for muscle contraction (action).

73. Cell Structure Reflects Cell
Function
 Cells of renal tubule lining are cube-
shaped (helps with their function of
absorption/secretion)

74. Cell Structure Reflects Cell
Function
 Nerve cells: are long and thin to carry
impulses over distance.

75. Cell Structure Reflects Cell
Function
 Columnar epithelium with cilia on the
free surface lines of the respiratory
tract, fallopian tubes and uterus. The
cilia beat rhythmically to transport
particles.

76. Cell Structure Reflects Cell
Function
 Sperm cell has a tail or "flagellum"
which executes the lashing movements
to propel the sperm.

77. Cell Structure Reflects Cell
Function
 Red blood cells contain hemoglobin
which permits them to transport oxygen
(and carbon dioxide).

78. Animal Cell vs. Plant Cell

79. Comparing Plant and Animal Cells
Plant Animal