1. Introduction to Cells Cells are the basic units of organisms
Cells can only be observed under microscope
Basic types of cells:
Animal Cell
Plant Cell
Bacterial Cell

2. Cell Structure and Function
Cells are a collection of living matter enclosed by a barrier that separates the cell from its surroundings

3. Every Cell Contains:
Membrane – thin layer of material that serves as a covering or lining
Structure containing the cells genetic material

4. Number of Cells Organisms may be: Unicellular – composed of one cell
Multicellular- composed of many cells that may organize

5. Cells May be Prokaryotic or Eukaryotic
Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles
Eukaryotes include most other cells & have a nucleus and membrane-bound organelles

6. Prokaryotes Genetic material is not contained in the nucleus
Less complicated than eukaryotic cells
Bacteria are examples of prokaryotes

7. Eukaryotic Cell Larger and more complex than prokaryotes
Plants, Animals, Fungi are eukaryotes
Contain 3 basic cell structures:
Nucleus – contain genetic info
Cell Membrane
Cytoplasm with organelles

8. Nucleus
Nucleus – a large membrane-enclosed structure that contains the cell’s genetic material in the form of DNA
Controls many of the cells activities

9. Cell Theory All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.

10. Basic Structure of a Eukaryotic Cell

11. Two Main Types of Eukaryotic Cells
Animal Cell
Plant Cell

12. Plant Cell Plant Cell Smooth endoplasmic Vacuole reticulum (free)
Nuclear
envelope
Ribosome
(attached)
(free)
Smooth endoplasmic
reticulum
Nucleus
Rough endoplasmic reticulum
Nucleolus
Golgi apparatus
Mitochondrion
Cell wall
Cell
Membrane
Chloroplast
Vacuole
Plant Cell

13. Animal Cell Ribosome (attached) Nucleolus Ribosome (free) Nucleus Cell
Membrane
Nuclear
envelope
Mitochondrion
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus

14. Organelles – “little organs”
Very small size
Can only be observed under a microscope
Have specific functions
Found throughout cytoplasm

15. Nucleus “The Control Center”
Contains nearly all the cell’s DNA with the codes for the cells proteins and other molecules
Surrounded by the nuclear envelope
Full of nuclear pores
Chromatin – DNA and proteins spread throughout the nucleus

16. Nucleus Chromosomes – condensed form of chromatin
Passes on from one generation to the next
Nucleolus – place where ribosomes are assembled

17. Ribosomes “Protein Factories” Small particles of RNA and protein
Located in the cytoplasm
Organelle where proteins are assembled
Ribosomes get codes for proteins from nucleus

18. Endoplasmic Reticulum
“Highway System of the cell”
Internal membrane system
Transports-
Proteins
Other macromolecules
Two types:
Smooth
Rough

19. Smooth & Rough Endoplasmic Reticulum
Smooth ER lacks ribosomes & makes proteins USED In the cell
Rough ER has ribosomes on its surface & makes proteins to EXPORT

20. Golgi Apparatus “The Shippers of the cell”
Closely stacked membranes, resembles stacks of pancakes
Modifies, sorts, and packages proteins from the ER for storage or secretion
Sends proteins to their final destination

21. Lysosomes “Clean-up Crews” Small organelles filled with enzymes
Breaks down lipids, carbohydrates, and proteins into smaller molecules that can be reused by the cell
Also breaks down old organelles

22. 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
Two membranes – outer and inner
Inherit mitochondria from mother
Contains its own DNA

23. Vacuole Saclike structure Stores materials
Water, salts, proteins, carbohydrates
Plants have a large central vacuole
Single-celled organisms use a contractile vacuole to maintain homeostasis

24. Cell or Plasma Membrane
Cell membrane
Living layer
Controls the movement of materials into and out of the cell
Selectively permeable

25. Cytoplasm of a Cell Cytoplasm
Jelly-like substance enclosed by cell membrane
Provides a medium for chemical reactions to take place

26. Cytoskeleton Supporting framework of the cell
Cytoskeleton = cell skeleton
Many components
Microtubules / microfilaments made of proteins.
Move organelles w/in the cell.

27. Cytoskeleton Continued
Microtubules / Microfilaments make up
Cilia
Flagella
Used in cellular locomotion

28. Different kinds of animal cells
white blood cell
red blood cell
cheek cells
sperm
nerve cell
muscle cell
Amoeba
Paramecium

29. Now let’s talk about structures only found in PLANT Cells!!

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

31. Chloroplast
Organelles that capture energy from sunlight and convert it into chemical energy
Photosynthesis
Two membranes
Contains pigment chlorophyll

32. Eukaryotic Cell Organelles and Function
Cell Wall
Function: provides support and protection to the cell membrane
Found outside the cell membrane in plant cells

33. Different kinds of plant cells
Onion Epidermal Cells
Root Hair Cell
root hair
Guard Cells

34. Similarities between plant cells and animal cells
Both have a cell membrane surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria

35. Differences between plant cells and animal cells
Animal cells Plant cells
Relatively smaller in size
Relatively larger in size
Irregular shape
Regular shape
No cell wall
Cell wall present

36. Differences between Plant Cells and Animal Cells
Animal cells Plant cells
Vacuole small or absent Large central vacuole
Glycogen as food storage starch as food storage
Nucleus at the center Nucleus near cell wall

37. Endosymbiont Hypothesis
Lynn Margulis U-Mass.
Found that mitochondria / chloroplasts did not fit the roles of organelles.
They had unusual properties.

38. 3 properties of Mito / Cplasts
Contain own DNA
Both surrounded by 2 membranes
Most organelles only surrounded by one membrane.
Both reproduce separately from the rest of the cell

39. Margulis’s Model
Both Mitochondria / Chloroplasts had ancestors that were free-living organisms.
These formed endosymbiotic relationships with other cells.
Over time offsprings of these organisms lost their independence becoming organelles of larger cells.

40. Further Evidence
Studies of DNA in chloroplasts show that they are much like the DNA prokaryotic cells.
Mitochondria / chloroplasts contain their own ribosomes and make many of their own proteins.
These ribosomes are smaller / chemically different from those in eukaryotic cells.
More closely resemble ribosomes in prokaryotic cells.

41. Levels of organization
Cells are grouped together and work as a whole to perform special functions
Known as “Cell Specialization”

42. Tissue A group of similar cells to perform a particular function
Animals : epithelial tissue, muscular tissue
Plants : vascular tissue, mesophyll

43. Organ
Different tissues group together to carry out specialized functions
Heart : consists of muscles, nervous tissue and blood vessels
Leaf : consists of epidermis, mesophyll and vascular tissue

44. The Structures of a Leaf (Plant Organ)
Chloroplast
Palisade Mesophyll Cell
Spongy Mesophyll Cell
Air Space
Stoma

45. The Structures of a Heart (Animal Organ)

46. Organ System
Several organs and tissues work together to carry out a particular set of functions in a co-ordinated way
Human : digestive, respiratory, excretory, circulatory and reproductive systems
Plant : root and shoot systems

47. Human Body Systems Examples of systems : Digestive System
Respiratory System
Circulatory System
Nervous System
Reproductive System

48. Examples of a Human Body System

49. Examples of a Human Body System

50. Levels of Organization
CELLS (muscle cells,nerve cells)
TISSUES (muscle, epithelium)
ORGANS (heart, lungs, stomach)
SYSTEMS (circulatory system)
ORGANISM (human)

51. It’s You!