1. Unit 2: Cellular Biology
PPT 2:
LESSONS 2.4, 2.5, 2.6, 2.7, 2.8, 2.9

2. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

3. Definition of a Cell
A cell is the smallest unit that is capable of performing life functions.

4. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell
Nerve Cell

5. Discovery of Cells Robert Hooke (mid-1600s)
Observed sliver of cork with a microscope
Saw “row of empty boxes”
Coined the term cell

6. Cell theory (1839)Theodor Schwann & Matthias Schleiden
“ all living things are made of cells”
1889 (50 yrs. later) Rudolf Virchow
“all cells come from other cells”

7. Cell Theory All living things are made up of cells.
Cells are the smallest working units of all living things.
All cells come from preexisting cells through cell division.

8. Cell Size

9. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

10. Age of the Earth
The universe as a whole is estimated to be about 13.8 billion years old.
Our solar system (and our planet, Earth) is estimated to have begun approximately billion years ago.
The Milky Way Galaxy, our home turf.

12. Glow in the dark squid… how does it do that?

13. Vibrio fischeri
Glow in the dark bacteria
Helps the squid survive in the deep ocean
Lives in fish and other marine life

14. Two Types of Cells Prokaryotes (prokaryotic cells)
Eukaryotes (eukaryotic cells)

15. Prokaryotes
Oldest of cell types, first appeared on Earth 3.8 billion years ago.
Domain Bacteria, Domain Archaebacteria
Very simple and small cells.
Do not have membrane-bound organelles,

16. Prokaryotes Do not have a real nucleus
Nucleoid: region of concentrated DNA (some have it, some don’t)
Can live in hostile environments.
ALL are Unicellular organisms, such as Bacteria
Escherichia coli

17. Prokaryotic Cells

18. Naming Shapes of Prokaryotes
Cocci = spherical (round)
Bacillus = rod shaped
Spirilla = helical (spiral)

19. Eukaryotes
First appeared on Earth approximately 1.5 billion years ago.
Complex internal structure, larger than prokaryotes
Have a nucleus, with DNA (genetic material) inside.
Contain organelles surrounded by coverings called membranes
Plant
Animal

20. Eukaryotes Can be both unicellular or multi-cellular
Most living organisms, including all known members of Kingdoms Protista, Fungi, Plantae, Animalia.

21. Video – Amoeba Sisters

22. How do the differences line up?
Prokaryotes
Organelles lack a membrane
Ribosomes are the only organelles
Genetic material floats in the cytoplasm (DNA and RNA)
Eukaryotes
Organelles covered by a membrane
Multiple organelles including ribosomes
Membrane covered Genetic material

23. How do the differences line up?
Prokaryotes
Circular DNA
Unicellular
Cells are smaller in size
Has larger number of organisms
Eukaryotes
Linear DNA
May be multicellular or unicellular
Cells are larger in size
Has smaller number of organisms

24. “Typical” Animal Cell Structure

25. “Typical” Plant Cell Structure

26. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

27. Surrounding the Cell Cell Membrane (ALL cells)
Cell Wall (Plants & Fungi, some bacteria, NOT animal cells)

28. Cell Membrane Found in ALL cell types Function: Surrounds the cell
Forms the barrier between the cell and its outer environment.
Selectively Permeable: Controls what enters or leaves the cell

29. Cell Membrane Structure:
Double layer of molecules called “phospholipids”.
Therefore, called a phospholipid bilayer

30. HYDROPHOBIC = WATER FEARING HYDROPHILIC = WATER LOVING
Cell Membrane
Phospholipids:
2 parts:
Head – hydrophilic
Tail – hydrophobic
HYDROPHOBIC = WATER FEARING
HYDROPHILIC = WATER LOVING

33. Cell Membrane Structure:
Embedded (stuck in) the phospholipid bilayer are several other molecules:
Cholesterol:
provides structure for the membrane
Proteins:
transport things in to or out of the cell
communicate with the outside environment

34. Cell Membrane Fluid Mosaic Model of the Membrane:
Many molecules embedded in the membrane make it look like a mosaic (yes, like art)
The molecules are not fixed in place, they are fluid - they move side-to-side frequently.

36. Fluid Mosaic Model

37. Cell Wall Most commonly found in PLANT, BACTERIA & FUNGI cells
Surrounds the cell membrane (on the outside)
Supports and protects the cell

38. Cytoplasm Found in ALL cell types
Function: Suspends (holds) the internal cells structures and organelles
Structure: A thick, gel-like material that fills the inside of the cell
Made of nutrients, enzymes, and water.

39. Nucleus Found ONLY in Eukaryotic cells
Separated from the cytoplasm by the nuclear membrane
Function:
Controls the cell’s activities (BRAIN of the Cell)
Contains genetic material (DNA)

40. Nuclear Envelope Function: Surrounds the nucleus Structure:
Has 2 layers:
Inner membrane
Outer membrane
Openings (called pores) allow material to enter and leave nucleus

41. Nuclear Membrane/Envelope

42. Chromosomes Inside nucleus Made of DNA Function:
DNA is genetic material: instructions for construction, control, traits & characteristics of the cell/organism

43. Nucleolus Structure: dark spot inside nucleus
Function: Creates RNA, which is used to build proteins

44. Nucleus

45. Cytoskeleton Prokaryotes & eukaryotes
Structure: Network of protein strands, like a skeleton
Function:
Supports and maintains shape of cell
Involved in cell movement and internal transport

47. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

48. Endoplasmic Reticulum (ER)
Function: Moves materials around in cell
Structure: folded phospholipid bilayer (membrane material)
2 Types:
Rough (pictured): has ribosomes embedded in surface (black dots)
Smooth: no ribosomes.
Endoplasmic reticulum

49. Endoplasmic Reticulum Around the Nucleus

50. Smooth ER vs. Rough ER More Functions:
Rough ER - ribosomes on the ER make proteins, the ER modifies the proteins
Smooth ER – no ribosomes. makes lipids

51. Endoplasmic reticulum

52. Ribosomes Each cell contains thousands of ribosomes
Found on endoplasmic reticulum, on nuclear membrane & floating throughout the cytoplasm of the cell
Function: Make proteins to build cell structures

53. Mitochondria Found in BOTH ANIMAL & PLANT cells Function:
Produces energy (ATP) for the cell
“Powerhouse of the Cell”
Cellular Respiration – a chemical reaction that breaks down fats & carbohydrates into ATP (energy).

54. Mitochondria Structure: Outer membrane inner folded membrane (cristae)
Matrix (cytoplasm)
mitochondrial DNA

55. Golgi Apparatus ‘Packaging & shipping station‘ of the cell Function:
Packages materials (proteins) for transport
Preparing to move materials out of the cell
Structure: Made of a stack of flattened membrane sacs.

57. Lysosome Structure: Membrane sac containing strong enzymes (chemicals)
Produced by the Golgi apparatus
Function:
Digests proteins, fats, and carbohydrates, and damaged organelles
Transports undigested material to cell membrane for removal
Cell breaks down if lysosome explodes! (“suicide bags”)

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

59. Cytoplasm Extracellular fluid
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Cytoplasm
Endoplasmic
reticulum
Food
vesicle
Golgi
apparatus
Lysosomes
Transport
vesicle
Old or damaged
organelle
Plasma
membrane
Digestion of
food particles
or cells
Breakdown
of old
organelle
Extracellular
fluid

60. Vacuoles Found in ANIMAL & PLANT cells
Structure: Membrane-bound sacs, contains a water solution
Function:
For storage, digestion, and waste removal
Help plants maintain shape (central vacuole)

61. Central Vacuole in Plants

62. Chloroplast Found ONLY in PLANT cells Contains green chlorophyll
Function: Site of photosynthesis
Photosynthesis: chemical reaction that uses light energy and carbon dioxide to make oxygen and sugar
Have their
own DNA

63. Centrioles Found ONLY in ANIMAL cells Structure:
Cylindrical structures found near the nucleus
Made of hollow, tubular structures arranged in bundles
Function:
Used in cell division

65. Cell City Song

66. Organelles Rap

67. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

68. Mitochondria vs. Chloroplasts
Mitochondria make energy (ATP) from food molecules through cellular respiration
Chloroplasts make food molecules from light energy through photosynthesis

69. Plant vs. Animal Cells

71. Plant Cell

73. Plant vs. Animal Cells

74. Animal Cells vs. Plant Cells

75. Endoplasmic reticulum
Plant vs. Animal Cells
PLANT CELL
ANIMAL CELL
Cell membrane
Mitochondria
Golgi apparatus
Nucleus
Cytoskeleton
Ribosomes
Endoplasmic reticulum
Lysosomes
HAVE:
Cell Wall
LARGE vacuoles
Chloroplasts
DO NOT HAVE:
Centrioles
HAVE:
Centrioles
DO NOT HAVE:
Cell Wall
LARGE vacuoles
Chloroplasts

76. Prokaryotes vs. Eukaryotes

78. Unit 2 Cellular Biology Part 2 Table Of Contents
2.4 Cell Theory 2.5 Prokaryotic vs. Eukaryotic Cells 2.6 Membrane, Cytoplasm, Nucleus 2.7 Organelles 2.8 Plant vs. Animal Cells 2.9 Cellular Movement

79. Flagella Usually found on aquatic cells (living in water)
Both prokaryotic and eukaryotic organisms
Structure: long, whip like structures
Function: help the cell move (like a tail)
The only flagellated cell in the human body: the sperm cell

80. Cilia Cilia are found on eukaryotic cells. Structure:
Tiny hair-like structure present on the surface of cell.
Can number in the hundreds of thousands per cell.
Function: Used for movement (like oars on a boat), or absorption of nutrients
False-colored cilia in a lung

81. Flagella & Cilia

82. Pseudopodia literally means “false feet”.
Structure: projections of the cell’s cytoplasm & membrane
Function: movement
Also used to engulf (swallow) molecules too large to pass through the cell membrane
Amoeba and macrophages (white blood cells) move using pseudopodia

83. Microvilli
They are found on the surface of the cells that line the small intestine of animals.
Structure: tiny finger-like projections on the surface of certain types of cells.
Function: absorption of materials because they increase the surface area of the cell membrane.
Intestinal microvilli, TEM

84. Cellular Movement
Flagella
Cillia
Pseudopod

85. Cell Differentiation
Cell specialization occurs during the development of a multi-cellular organism.
The genetic information necessary for all cellular functions remains in each cell but may not be used.

86. ANY QUESTIONS?