THIS IS A MACHINE THAT REQUIRES SEVERAL PARTS TO DO ITS JOB. THINK ABOUT ITS JOB THEN ANSWER THE FOLLOWING: - ARE THERE ANY PARTS YOU CAN TAKE OUT AND IT STILL FUNCTION? - ARE THERE ANY PARTS THAT YOU ABSOLUTELY CANNOT REMOVE WITHOUT CHANGING ITS FUNCTION? Opening Assignment 1

2 Basic Structure of a Cell

3 Discovery of the Cell Robert Hooke (1665) → examined a slice of cork under the microscope, he saw boxes that he called cells Anton Van Leeuwenhoek (1675) → looked at pond water and found small living organisms – “animalcules”

4 Formation of the Cell Theory Matthias Schleiden → cells compose every part of plants Theodor Schwann → cells compose every part of animals Rudolph Virchow → cells come only from other cells Rudolph Virchow

5 The Cell Theory 1.All living organisms are composed of one or more cells 2.In organisms, cells are the basic units of structure and function 3.Cells are produced only from existing cells

History & Discovery Questions What are some ways our knowledge has advanced regarding cells, based on the developments done by these & other scientists? (think of some current research being done and information in the news) Think about the part of the cell theory that states cells are produced only from pre- existing cells. What does this mean? What does it make you think about? 6

7 Review of Introduction to Cells Cells are the basic units of organisms Cells can only be observed under microscope Basic types of cells: Animal CellPlant Cell Bacterial Cell

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

9  Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles – small single-celled  Eukaryotes include most other cells & have a nucleus and membrane-bound organelles (plants, fungi, & animals) – larger than prokaryotes and can be either unicellular or multicellular Cells May be Prokaryotic or Eukaryotic

Prokaryote & Eukaryote Questions If Prokaryotes don’t have a nucleus does that mean that they do not have any DNA? Eukaryotes have membrane-bound organelles, which are specialized to perform specific cellular tasks. What characteristic of life does this best coincide with? 10

11 Prokaryotes Nucleoid region contains the DNA Cell membrane & cell wall Contain ribosomes (no membrane) to make proteins in their cytoplasm

12 Two Main Types of Eukaryotic Cells Plant Cell Animal Cell

13 Organelles Very small size Can only be observed under a microscope Have specific functions Found throughout cytoplasm

ORGANELLES & OTHER STRUCTURES OF THE CELL 14

15 Nucleolus

16 Ribosomes

17 Proteins

18 Endoplasmic Reticulum

19 Golgi Apparatus

20 Lysosome

21

22

23 Controls the normal activities of the cell Bounded by a nuclear membrane Contains chromosomes Control Organelle Nucleus

24 Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics Nucleus More on the Nucleus

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

26 Contains organelles to carry out specific jobs Examples: chloroplast & mitochondrion Cytoplasm More on Cytoplasm

27 Lies immediately against the cell wall in plant cells Made of protein and phospholipids Selectively permeable Cell membrane Surrounding the Cell

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

29 Rod shape Site of Cellular respiration Cell Powerhouse Mitochondrion ( mitochondria )

30 Active cells like muscles have more mitochondria Burn sugars to produce energy ATP In Animal Cells: Mitochondria

31 Contain the green pigment chlorophyll Traps sunlight to make sugars (food) Process called photosynthesis Plant Cell Organelles Chloroplast

32 Dead layer Large empty spaces present between cellulose fibers Freely permeable Cell wall Plant Cell

33 Plant Cell Made of cellulose which forms very thin fibers Strong and rigid Found in plant cells Cell wall

34 Protect and support the enclosed substances (protoplasm) Resist entry of excess water into the cell Give shape to the cell Cell wall Plant Cell

35 Have a large central vacuole Surrounded by tonoplast Contains cell sap Sugars, proteins, minerals, wastes, & pigments Plant Cell Organelles Vacuole

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

37 mitochondrion nucleus glycogen granule cell membrane cytoplasm Animal cell No cell wall or chloroplast Stores glycogen in the cytoplasm for food energy vacuole

38 Animal Cell Organelles Near the nucleus Paired structures Help cell divide

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

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

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

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

43 Microscopes

44 Compound Microscope Instrument for observing small objects Magnify images up to 2000X their size

45 Different parts of a compound microscope

46 Eyepiece Fine adjustment Arm Stage Condenser control knob Base Body tube Coarse adjustment Iris diaphragm Revolving nosepiece Objective Clip Condenser Mirror

47 Electron Microscope Transmission EM (TEM) –Uses a beam of electrons to produce an enlarged image of very thinly sliced specimen on screen or photographic plate –Image focused by magnetic lenses –200,000X magnification –Cannot be used to view living specimens

48 Scanning EM (SEM)Scanning EM (SEM) –3D image –Specimens not sliced for viewing –Surface sprayed with fine metal coating –Also uses electron beam and fluorescent screen or photographic plates –100,000X magnification –Cannot be used to view living specimens

49 The cell is the Basic Unit of Life Cell is the smallest unit of living organisms Unicellular organisms are made of one cell only The cells of multicellular organisms are specialized to perform different functions –e.g. mesophyll cells for photosynthesis and root hair cells for water absorption

50 Levels of organization Cells are grouped together and work as a whole to perform special functions

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

52 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

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

54 The Structures of a Heart (Animal Organ)

55 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

56 Human Body Systems Examples of systems :  Digestive System  Respiratory System  Circulatory System  Nervous System  Reproductive System

57 Examples of a Human Body System

58 Examples of a Human Body System

59 Examples of a Human Body System Circulatory System

60 Examples of a Human Body System Nervous System

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

62 It’s You!