1 Basic Structure of a Cell

2 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

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

4 Two Main Types Cells (with DNA contained in the nucleus) Plant Cell Animal Cell copyright cmassengale

5 Organelles are inside of all cells Very small size Can only be observed under a microscope Have specific functions Found throughout cytoplasm copyright cmassengale

6 Organelles Found in Cells Examples of Organelles include: Lysosomes – digests & gets rid of wastes -like a cell’s stomach/digestive system copyright cmassengale

7 Lysosomes Contain digestive enzymesContain digestive enzymes Break down food, bacteria, and worn out cell parts for cellsBreak down food, bacteria, and worn out cell parts for cells Lyse (break open) & release enzymes to break down & recycle cell parts)Lyse (break open) & release enzymes to break down & recycle cell parts) copyright cmassengale

8 Lysosome Digestion Cells take in food by phagocytosis Lysosomes digest the food & get rid of wastes copyright cmassengale

9 Mitochondrion (plural = mitochondria) “Powerhouse” of the cell Generate cellular energy (ATP) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria Site of CELLULAR RESPIRATION (burning glucose/sugar) copyright cmassengale

10 What do mitochondria do? Burns glucose sugar to release energy (ATP) Stores energy as ATP “Power plant” of the cell copyright cmassengale

11 Rod shape Site of Cellular respiration – provides energy Cell Powerhouse Mitochondrion ( mitochondria ) copyright cmassengale

12 Active cells like muscles have more mitochondria Burn sugars to produce energy “ATP” In All Cells: Mitochondria copyright cmassengale

13 Lies immediately against the cell wall in plant cells Made of protein and phospholipids (fat) Selectively permeable, has holes so some stuff passes through Cell membrane Surrounding all Cells copyright cmassengale

14 Cell or Plasma Membrane Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells Controls what enters or leaves the cell Living layer copyright cmassengale

15 Living layer Controls the movement of materials into and out of the cell Selectively permeable (stuff goes in/out) Cell membrane Cell or Plasma Membrane copyright cmassengale

16 Nonliving layer Gives structure and shape to plant and bacterial cells Not found in animal cells (animals have bones instead) Cell wall Plant cell organelle:Cell Wall copyright cmassengale

17 Jelly-like substance enclosed by cell membrane Provides a medium for chemical reactions to take place Cytoplasm Cytoplasm of all Cells copyright cmassengale

18 Contains organelles to carry out specific jobs Examples: chloroplast & mitochondrion float in the cytoplasm Cytoplasm More on Cytoplasm copyright cmassengale

19 Largest animal cell organelle Controls the normal activities of the cell Contain the DNA (chromosomes/genes) Control Organelle in all cells Nucleus copyright cmassengale

20 Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics Nucleus copyright cmassengale

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

22 Chloroplasts (found only in Plant cells) Contains enzymes & pigments for Photosynthesis Never in animal or bacterial cells Photosynthesis – food making process copyright cmassengale

23 Chloroplasts Found only in producers/plants (organisms containing chlorophyll) Use energy from sunlight to make own food (glucose) Energy from sun stored in the Chemical Bonds of Sugars copyright cmassengale

24 Dead layer Large empty spaces present between cellulose fibers Freely permeable Cell wall Plant Cell Only: copyright cmassengale

25 Plant Cell Made of cellulose which forms very thin fibers Strong and rigid supports plants so they stand upright Cell wall copyright cmassengale

26 Flat sides that protect and support the enclosed substances Resist entry of excess water into the cell Give shape to plant cells Cell wall Plant Cell Only copyright cmassengale

27 Lies immediately against the cell wall in plant cells Pushes out against the cell wall to maintain cell shape Cell Membrane in Plants Plants have a cell membrane too! copyright cmassengale

28 Vacuoles Fluid filled sacks for storage Small or absent in animal cells Plant cells have a large Central Vacuole copyright cmassengale

29 large central vacuole= biggest organelle in plant cells Contains cell sap Sugars, proteins, minerals, wastes, & pigments Vacuole copyright cmassengale

30 Kinds of Plant cells Xylem cells Pollen Guard Cells copyright cmassengale

31 mitochondrion nucleus glycogen granule cell membrane cytoplasm Animal cell No cell wall No chloroplast Roundish shapes vacuole copyright cmassengale

32 Different kinds of animal cells white blood cell red blood cell cheek cells sperm nerve cell muscle cell Amoeba Paramecium copyright cmassengale

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

34 Differences between plant cells and animal cells Animal cellsPlant cells Relatively smaller in size Irregular shape No cell wall Relatively larger in size Regular flat sides Cell wall present copyright cmassengale

35 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 copyright cmassengale