1 Basic Structure of a Cell

History of Cell Theory mid 1600s – Anton van Leeuwenhoek –Improved microscope, observed many living cells mid 1600s – Robert Hooke –Observed many cells including cork cells –Named the cell 1850 – Rudolf Virchow –Proposed that all cells come from existing cells

SCI.9-12.B [Indicator] - Recall the three major tenets of cell theory (all living things are composed of one or more cells; cells are the basic units of structure and function in living things; and all presently existing cells arose from previously existing cells). 3

SCI.9-12.B-2 - [Standard The student will demonstrate an understanding of the structure and function of cells and their organelles.] 4

*Cell Theory 1.All organisms consist of 1 or more cells. 2.Cell is the smallest unit of life. 3.All cells come from pre-existing cells.

Observing Cells (4.1) Light microscope –Can observe living cells in true color –Magnification of up to ~1000x –Resolution ~ 0.2 microns – 0.5 microns

Observing Cells (4.1) Electron Microscopes –Preparation needed kills the cells –Images are black and white – may be colorized –Magnifcation up to ~100,000 Transmission electron microscope (TEM) –2-D image Scanning electron microscope (SEM) –3-D image

SEM TEM

9 *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 copyright cmassengale

10 *Number of Cells Organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize copyright cmassengale

11  Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles  Eukaryotes include most other cells & have a nucleus and membrane- bound organelles (plants, fungi, & animals) *Cells May be Prokaryotic or Eukaryotic

12 SCI.9-12.B [Indicator] - Compare the structures and organelles of prokaryotic and eukaryotic cells.

13 *Prokaryotes Nucleoid region contains the DNA Cell membrane & cell wall Contain ribosomes (no membrane) to make proteins in their cytoplasm Only example is bacteria

14 *Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles

15 Two Main Types of Eukaryotic Cells Plant Cell Animal Cell

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

SCI.9-12.B [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm). 17

CYTOSKELETON MITOCHONDRIO N CENTRIOLES LYSOSOME GOLGI BODY SMOOTH ER ROUGH ER RIBOSOMES PLASMA MEMBRANE Fig. 4-15b, p.59 Chroma tin

19 Organelles Found in Cells Examples of Organelles include: Endoplasmic reticulum (rough & smooth) – canals for movement Golgi Bodies – wrap & export proteins Nucleolus – makes ribosomes Lysosomes – digests & gets rid of wastes Ribosomes – makes proteins

20 * Golgi Bodies Stacks of flattened sacsStacks of flattened sacs Have a shipping side & a receiving sideHave a shipping side & a receiving side Receive & modify proteins made by ERReceive & modify proteins made by ER Transport vesicles with modified proteins pinch off the endsTransport vesicles with modified proteins pinch off the ends Transport vesicle

21 *Lysosome Contain digestive enzymesContain digestive enzymes Break down food and worn out cell parts for cellsBreak down food and worn out cell parts for cells Programmed for cell death (lyse & release enzymes to break down & recycle cell parts)Programmed for cell death (lyse & release enzymes to break down & recycle cell parts)

22 *Nucleolus Cell may have 1 to 3 nucleoli Cell may have 1 to 3 nucleoli Inside nucleusInside nucleus Disappears when cell dividesDisappears when cell divides Makes ribosomes that make proteinsMakes ribosomes that make proteins

SCI.9-12.B [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm). 23

24 *Smooth & Rough Endoplasmic Reticulum Smooth ER lacks ribosomes & makes lipids also detoxifies poisons from medicine and alcohol Rough ER has ribosomes on its surface & makes proteins to EXPORT

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

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

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

SCI.9-12.B [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm). 28

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

Read this! Proteins and carbohydrates on the outside of cells give cells their “identity.” This lets the immune system know that the cells belong in that body. Transplanted organs are often rejected by the body because the immune system recognized the proteins and carbs as not belonging to that person’s body. 30

SCI.9-12.B [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm). 31

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

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

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

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

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

SCI.9-12.B [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm). 37

Chromoplast – gives plants colors other than green. Amyloplast – stores starch in plants- found in potatoes 38

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

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

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

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

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

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

47 Animal Cell Organelles Near the nucleus Paired structures Help cell divide Not found in plant cells

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

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

50 *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

51 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

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

53 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

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

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

56 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

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

58 The Structures of a Heart (Animal Organ)

59 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 copyright cmassengale

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

61 Examples of a Human Body System

62 Examples of a Human Body System

63 Examples of a Human Body System Circulatory System

64 Examples of a Human Body System Nervous System

65 It’s You!

Terms for your test Ribosomes Chloroplast *Photosynthesis Mitochondria *Prokaryotic *Eukaryotic Smooth ER Rough ER *Amyloplasts *Chromoplasts Cell membrane 66 Golgi bodies Chromatin Centrioles in centrosome Chromosomes Nucleolus Vacuoles *Difference b/w prokaryotic/eukaryotic smooth/rough ER plant/animal cell