This document provides an overview of cell structure and function. It begins with the cell theory and key discoveries in cell biology. The main parts of prokaryotic, plant, and animal cells are described along with their functions. Key differences between prokaryotic and eukaryotic cells, and plant and animal cells, are highlighted. Important cellular structures like the nucleus, mitochondria, chloroplasts, and cell membrane are explained. The document concludes with a discussion of the secretory pathway and defines important cellular terms.

1. CCeellllss -- 22001144
Structure and Function

2. BByy tthhee eenndd ooff tthhiiss cchhaapptteerr II mmuusstt
kknnooww>>>>>>>>
 What are the parts to the cell theory and 2 exceptions to the
cell theory.
 What are the organelles and functions of the organelles in a
Animal cell? Plant Cell? A Basic Prokaryotic Cell?
 What are the structural differences between a Eukaryotic and
Prokaryotic cell?
 What are the structural differences between a Plant and
Animal cell?
 What is the Secretory pathway?****
 Can I draw/diagram a plant, animal, and bacterial cell with all
the proper organelles

3. VVooccaabbuullaarryy
 Prokaryote (ic)
 Eukaryote (ic)
 Cell Theory
 Organelle
 cytoplasm
 Nucleus
 Nucleolus
 Cell membrane
 Nuclear envelope
 Chromatin
 Ribosome
 Endoplasmic reticulum
– Smooth
– Rough
 Golgi Apparatus
 Mitochondria
 Chloroplast
 Cell wall
 Vacuole
 Lysosome
 peroxisome
 Centriole
 Cytoskelton
 Slime capsule
 Mesosome
 Plasmid
 Naked DNA

4. SSeeccttiioonn 11:: IInnttrroodduuccttiioonn ttoo tthhee CCeellll

5. Figure 3A

6. DDiissccoovveerryy ooff CCeellllss
The invention of the lens
Robert Hooke (1665):
observed a thin slice of cork
(dead plant cells) with a
microscope.
observed as “little boxes”
(cells).

7. DDiissccoovveerryy ooff CCeellllss
Anton van Leeuwenhoek
(1675): was the first person to
observe living cells.

8. TThhee CCeellll TThheeoorryy
Who developed the cell theory?
– Matthias Schleiden (1838):
concluded that all plants are
composed of cells
– Theodor Schwann (1839):
concluded that all animals are
composed of cells
– Rudolph Virchow (1855):
determined that cells come
only from other cells

9. TThhee CCeellll TThheeoorryy
1. All living things are composed of one
or more cells.
2. Cells are organisms’ basic units of
structure and function.
3. Cells come only from existing cells.

10. EEXXCCEEPPTTIIOONNSS
Skeletal muscles are made of fibers with
hundreds of nuclei. Much larger than
regular cells.
Bone, blood and cartilage have
extracellular material…proteins and fluids.
Mitochondria and chloroplast contain DNA
Viruses – have DNA and RNA surrounded
by a protein coat!! NOT classified as a
cell!

11. NNeeeeddeedd CCyyttoollooggiiccaall DDeeffiinniittiioonnss::
 Cell – basic unit of structure and function in a living organism.
 Organelle – tiny structures in cells with specific functions.
 Tissue – collection of cells that develop in the same way
 Organs – groups of tissue that combine to form a single
structure.
 Organ System – groups of organs that together carry out a
process
 Autotroph – organism that can make its own food.
(photosynthetic)
 Heterotroph – organism that cannot make its own food.
 Differentiate – the ability of multicellular organisms to have
cells that specialize in a certain function.

12. CCeellll DDiivveerrssiittyy--
SSiizzee

13. Fig. 3.1

14. CCEELLLL SSIIZZEE
Remember: (n = nano, μ = micro)
• 1μm =.001mm
• 1nm = .001μm)
Molecules – 0.5 – 1nm
Membranes - 10nm
Viruses – 50 – 100 nm
Bacteria – 1 – 5 μm
Organelles – 5 – 10 μm
Cells – 10 – 100 μm

15. CCeellll DDiivveerrssiittyy-- SSiizzee
Biggest Cells:
6 inches long, 5 inches wide, 3 pounds
Smallest Cells:
Longest Cells:
Ostrich Egg

16. CCeellllss aanndd SSiizzeess
Magnification =
size of image
divided by the
size of the
specimen

17. CCeellll DDiivveerrssiittyy-- SShhaappee
Cells differ widely in shape.
Most cells are roughly
cuboidal or spherical.

18. CCeellllss
DDiiffffeerreennttiiaattee
Differentiation: Cells within
a multi cellular organism
specialize their function.
Specialized cells have switched on
particular genes (expressed) that
correlate to these specialist
functions.
These specific gene expressions
produce particular shapes, functions
and adaptations within a cell.

19. PPrrookkaarryyoottiicc CCeellllss
Cells Video – You’ll Love this one!!!!

20. PPrrookkaarryyootteess vvss.. EEuukkaarryyootteess
AANN OOvveerrvviieeww !!!!
PROKARYOTIC
 LACK membrane bound
organelles
 Simpler
 Autotrophs
 Naked DNA
 1-10 microns
 All bacteria
 All single-celled
 First cells to evolve
EUKARYOTIC
 HAVE membrane bound
organelles
 Complex
 Heterotroph/Autotroph
 Chromosomes
 10-100 microns
 All other organisms
 Single / multicellular
 Evolved from prokaryotes

21. Prokaryotic Cell

22. Fig. 3.3.a

23. Fig. 3.3

24. PPrrookkaarryyoottiicc CCeellll PPaarrttss
Cell wall –
• Protection and support
• Shape
• NOT made of cellulose
• Made of PEPTIDOGLYCAN
Slime Capsule (encapsulated)
• Protection
• Not easy to lyse or hydrolyze
• Difficult to kill ….pathogenic

25. PPrrookkaarryyoottiicc CCeellll PPaarrttss
Plasma membrane
• Controls passage of materials
• Selectively permeable (semi permeable)
Flagella
– Movement in a liquid environment
Pilli (us)
– Hair like projection
– Help bacteria stick to its background
– Allows 2 bacterial cells to stick together:
conjugation!!

26. PPrrookkaarryyoottiicc CCeellll PPaarrttss
Ribosome – protein synthesis
Plasmid – small circular DNA chain.
Codes for synthesis of certain proteins.
Used in genetic engineering.

27. PPrrookkaarryyoottiicc CCeellll PPaarrttss
Ribosome – protein synthesis
Plasmid – small circular DNA chain.
Codes for synthesis of certain proteins.
Used in genetic engineering.

28. PPrrookkaarryyoottiicc CCeellll PPaarrttss
Naked DNA – Naked nucleic acid. DNA not
surrounded by a membrane. Carries genetic
code. Located in the “nucleoid” region.
Mesosome
• Helps in cell division
• Increases surface area
• In aerobic bacteria: holds respiratory chain
• In photosynthetic bacteria: holds photosynthetic pigments.

29. Fig. 3.3.b

30. THE PROKARYOTIC CELL

32. FFiigguurree 77..44xx22 EE.. ccoollii FFrroomm aann EElleeccttrroonn MMiiccrrooggrraapphh

33. Other Characteristics ooff PPrrookkaarryyootteess

34. FFoorrmm:: ccooccccii,, bbaacciillllii,, ssppiirriillllaa

35. Prokaryotic CCeellllss ddiivviiddee bbyy bbiinnaarryy
ffiissssiioonn

36. EEuukkaarryyoottiicc CCeellllss

37. Fig. 3.4

38. Fig. 3.4.a

39. Fig. 3.4.b

40. KNOW HOW TO LOCATE AND BE ABLE TO
DRAW AND LABEL…..
ANIMAL PLANT

41. TThhee PPaarrttss ooff tthhee CCeellll
Each living cell carries out the tasks of taking
food, transforming food into energy, getting rid of
wastes, and reproducing.
Most eukaryotic cells have three main
components:
– Cell Membrane
– Cytoskeleton
– Nucleus

42. AAnniimmaall CCeellll
Now let
Annotate this
picture with all
the functions of
each structure
named

43. LLiivveerr
CCeellll

44. SSttrruuccttuurree aanndd FFuunnccttiioonn ooff OOrrggaanneelllleess

45. CCeellll MMeemmbbrraannee
Structure:
– phospholipid bilayer with
proteins that function as
channels, markers, and
receptors
-also contains cholesterol
which provides rigidity
Function:
– selectively permeable
boundary between the cell
and the external
environment

46. Fig. 4.1

47. NNuucclleeuuss
Structure:
– Similar to cell membrane
– Contains nucleolus
Function: -
– storage center of cell’s DNA
– manages cell functions

48. Fig. 3.6.b

49. IInnssiiddee tthhee NNuucclleeuuss
Nuclear Envelope
– A double membrane
– Porous for movement of protein and ribosomes
Nucleolus
– Formation of ribosomes
Chromatin (somes)
– Contain DNA and protein
– Genetic material

50. CCyyttooppllaassmm
Structure: gelatin-like fluid that lies inside the cell
membrane (Watery)
Function: -
– Holds all organelle within cytoskeleton
– Holds nutrients
– Excellent conductor of electricity
– Holds dissolved wastes

51. CCyyttoosskkeelleettoonn
– Structure:
– a network of thin,
fibrous elements made
up of microtubules
(hollow tubes) AND
– microfilaments (threads
made out of actin)
Function: -
– acts as a support
system for organelles
-maintains cell shape

52. Fig. 3.12

53. Fig. 3.12.a1

54. Fig. 3.12.a2

55. Fig. 3.12.a3

56. Fig. 3.12.b1

57. Fig. 3.12.b2

58. Fig. 3.12.c1

59. Fig. 3.12.c2

60. Fig. 3.13.a

61. CCeennttrriioolleess
Structure:
– composed of nine
sets of triplet
microtubules
arranged in a ring
• Exist in pairs
Function:
– centrioles play a
major role in cell
division (mitosis)

62. Area where the
centrioles are
located:
CENTROSOME
Each centrosome:
2 centrioles
Not a part of plant
cells.
Fig. 3.13

63. RRiibboossoommeess
Structure: consist of two
subunits made of protein
and RNA.
Found alone, in groups
(poly) and on rER
Function: location of
protein synthesis.

64. Fig. 3.7.a

65. TThhee SSeeccrreettoorryy PPaatthhwwaayy
Endoplasmic Reticulum
Golgi Apparatus
Lysosome
Peroxisome

66. EEnnddooppllaassmmiicc RReettiiccuulluumm
Structure: a system of membranous tubes and
sacs
Function:
– intracellular “highway” (a path along which molecules
move from one part of the cell to another)
– Forms transport vesicles
Two types:
– Rough Endoplasmic Reticulum – always near
nucleus
– Smooth Endoplasmic Reticulum – attached to
rER

67. Fig. 3.7.b

68. RRoouugghh EEnnddooppllaassmmiicc RReettiiccuulluumm
Rough Endoplasmic
Reticulum (rER):
– prominent in cells that
make large amounts of
proteins
– Covered with
ribosomes

69. SSmmooootthh EEnnddooppllaassmmiicc RReettiiccuulluumm
Smooth Endoplasmic
Reticulum (sER):
– involved in the synthesis of
lipids and breakdown of
toxic substances
– Not covered with ribosomes

70. GGoollggii AAppppaarraattuuss
Structure: stacked flat sacs
Function: receives proteins
from the rER and distributes
them to other organelles or
out of the cell
– collects
– sorts
– packages
– Distributes

71. LLyyssoossoommeess
Structure: spherical
organelles that contain
hydrolytic enzymes within
single membranes
A type of vesicle
Function: breaks down
food particles, invading
objects, or worn out cell
parts

72. PPeerrooxxiissoommeess
Structure: spherical
organelles that contain
enzymes within single
membranes
A type of vesicle
Function: Degrade
hydrogen peroxide, a
toxic compound that can
be produced during
metabolism.

73. Fig. 3.8

74. SSeeccrreettoorryy PPaatthhwwaayy
rER packages protein into vesicles that
separate from ER
Vesicles travel and fuse with Golgi
Apparatus
Golgi modifies & repackages protein into
new secretory vesicles.
Secretory Vesicles released into
cytoplasm
Vesicles fuse with Cell Membrane
Contents released – SECRETION!

75. SSeeccrreettoorryy PPaatthhwwaayy
Fig. 3.8

76. MITOCHONDRIA

77. MMiittoocchhoonnddrriiaa
Structure: folded
membrane within an outer
membrane
– The folds of the inner
membrane are called
cristae
Function: -converts
energy stored in food into
usable energy for work
– cellular respiration

78. Fig. 3.11.a

79. Fig. 3.9

80. CCiilliiaa aanndd FFllaaggeellllaa
Structure: hair-like organelles that extend from the
surface of cells
– When they are present in large numbers on a
cell they are called cilia
– When they are less numerous and longer they
are called flagella
– Both organelles are composed of nine pairs of
microtubules arranged around a central pair.
Function: cell motility

81. CCiilllliiaa aanndd FFllaaggeellllaa

82. PPLLAANNTT CCEELLLLSS
The other Eukaryotic Cell

83. Fig. 3.5.b

84. Fig. 3.5.a

85. Fig. 3.5.b

86. CCeellll WWaallll
Structure: rigid wall made
up of cellulose, pectin,
proteins, and
carbohydrates
Function: boundary
around the plant cell
outside of the cell
membrane that provides
structure and support

87. VVaaccuuoolleess
Structure: a sac of fluid
surrounded by a
membrane
– Very large in plants
Function: used for
temporary storage of
wastes, nutrients, and
water

88. CChhlloorrooppllaassttss
Structure: stacked
sacs (thylakoids) that
contain chlorophyll
surrounded by a
double membrane
Function:
photosynthesis
(conversion of light
energy to chemical
energy stored in the
bonds of glucose)

89. Fig. 3.10.a

90. O Structural Orrggaanniizzaattiioonn ooff EEuukkaarryyoottiicc
aanndd PPrrookkaarryyoottiicc CCeellllss

91. EEuukkaarryyootteess vvss.. PPrrookkaarryyootteess
Eukaryotes (animals,
plants, fungi, protists) and
prokaryotes (bacteria)
differ greatly in structure.

92. Prokaryotes Eukaryotes
nucleus? NO (nucleoid) YES
membrane-bound
organelles? NO YES (Many)
size 1 - 10 mm 10 - 50 mm
when evolved? 3.5 billion years ago 1.5 billion years ago
cytoplasm? YES YES
cell membrane? YES YES
cell wall? Some Do Plants
ribosomes? YES YES
DNA? Circular
Free Floating Chromosomes in Nucleus
examples Bacteria Plants, Animals, Fungi, and
Protists

93. PPllaanntt CCeellllss vvss.. AAnniimmaall CCeellllss
Animal cells are very similar to
plant cells except for the
following major differences:
– Animal cells do not contain
chloroplasts
– Animal cells are not
surrounded by cell walls
– The vacuoles in plants are
much larger than those of
animals

94. MMiiccrroossccooppee PPiiccttuurreess ooff aa
PPllaanntt CCeellll aanndd aann AAnniimmaall CCeellll
EEllooddeeaa HHuummaann CChheeeekk CCeellllss

95. CCeelllluullaarr LLeevveellss ooff OOrrggaanniizzaattiioonn
Cell
Tissue
Organ
Organ System
Organism

96. TTHHEE EENNDD!!