1 Basic Structure of a Cell copyright cmassengale

2 Characteristics of organisms? 1.Made of CELLS 2.REPRODUCE (species) 3.Maintain HOMEOSTASIS 4.GROW and DEVELOP 5.EXCHANGE materials with surroundings (water, wastes, gases) 6.RESPOND to environment 7.ORGANIZED 8.Require ENERGY (food) copyright cmassengale

3 CELL THEORY All living things are made of cells Cells are the basic unit of structure and function in an organism Cells come from the reproduction of existing cells copyright cmassengale

CELL SIZE Typical cells range from 5 – 50 micrometers (microns) in diameter copyright cmassengale4

5 First to View Cells In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cell walls) What he saw looked like small boxes copyright cmassengale

6 Cell Size and Types Cells, the basic units of organisms, can only be observed under microscope Three Basic types of cells include: Animal CellPlant Cell Bacterial Cell copyright cmassengale

7 ENDOSYMBIOTIC THEORY some organelles within cells were at one time free living cells themselves organelles with their own DNA Chloroplast and Mitochondria copyright cmassengale

8 Number of Cells Although ALL living things are made of cells, organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues, etc. copyright cmassengale bacteria butterfly

Multicellular Organisms Cells in multicellular organisms often specialize (take on different shapes & functions) copyright cmassengale9

All Cells –are surrounded by a barrier called a cell membrane. –contain DNA. copyright cmassengale10 Bacteria Animal cell

11 Prokaryotes Simplest type of cell Nucleoid region contains the DNA Surrounded by cell membrane & cell wall (peptidoglycan) ribosomes in their cytoplasm to make proteins Includes bacteria copyright cmassengale

12 Eukaryotes More complex type of cells HAVE a nucleus and membrane-bound organelles Cytoplasm with organelles Includes protists, fungi, plants, and animals “You are Eukaryotes” copyright cmassengale

13 Two Main Types of Eukaryotic Cells Plant Cell Animal Cell copyright cmassengale

14 Organelles Little organs Very small (Microscopic) Perform various functions for a cell Found in the cytoplasm May or may not be membrane-bound copyright cmassengale

15 Animal Cell Organelles Nucleolus Nucleus Nuclear envelope Ribosome (attached) Ribosome (free) Cell Membrane Rough endoplasmic reticulum Golgi apparatus Mitochondrion Smooth endoplasmic reticulum Centrioles copyright cmassengale

16 Plant Cell Organelles copyright cmassengale

17 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

18 Nonliving layer Supports and protects cell Made 0f; cellulose in plants peptidoglycan in bacteria chitin in Fungi Cell wall Cell Wall copyright cmassengale

19 Jelly-like substance Provides a medium for chemical reactions to take place Contains organelles Found in ALL cells Cytoplasm cytoplasm copyright cmassengale

20 Control center Contains the DNA Has a nuclear membrane with pores Has a fixed number of chromosomes that carry genes Genes control cell characteristics Nucleus Nucleus copyright cmassengale

21 Inside the Nucleus - The genetic material (DNA) is found DNA is spread out And appears as CHROMATIN in non-dividing cells DNA is condensed & wrapped around proteins forming as CHROMOSOMES in dividing cells copyright cmassengale

22 Nucleolus Inside nucleusInside nucleus Disappears when cell dividesDisappears when cell divides Makes ribosomes that make proteinsMakes ribosomes that make proteins copyright cmassengale

23 Ribosomes “Protein factories” for cell Join amino acids to make proteins Process called protein synthesis  copyright cmassengale

24 Cytoskeleton Helps cell maintain cell shape Also help move organelles around Made of proteins Microfilaments are threadlike Microtubules are tubelike copyright cmassengale MICROTUBULES MICROFILAMENTS

25 Centrioles Found only in animal cells Paired structures Made of bundle of microtubules Appear during cell division forming mitotic spindle Help to pull chromosome pairs apart to opposite ends of the cell copyright cmassengale

26 Mitochondria “Powerhouse” of the cell Generate cellular energy (ATP) active cells like muscle cells have MORE mitochondria In both plants & animal cells Surrounded by a DOUBLE membrane Folded inner membrane -CRISTAE Has its own DNA copyright cmassengale

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

28 Endoplasmic Reticulum - ER Two kinds of ER ---ROUGH & SMOOTH Network of hollow membrane tubules Connects to nuclear envelope & cell membrane Functions in Synthesis of cell products & Transport copyright cmassengale

29 Rough Endoplasmic Reticulum (ER) Has ribosomes on its surface Makes proteins for EXPORT out of cell copyright cmassengale

30 Smooth Endoplasmic Reticulum Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are USED INSIDE the cell copyright cmassengale

31 Golgi Bodies Look like a stack of pancakes Modify, sort, & package molecules from ER for storage OR transport out of cell copyright cmassengale

32 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 Programmed for cell death (AUTOLYSIS)Programmed for cell death (AUTOLYSIS) Lyse (break open) & release enzymes to break down & recycle cell parts)Lyse (break open) & release enzymes to break down & recycle cell parts) copyright cmassengale

33 Cilia & Flagella for cell movementfor cell movement Cilia are shorter and more numerous on cells copyright cmassengale Flagella are longer and fewer

34 Vacuoles Fluid filled sacks for storage Small or absent in animal cells Plant cells have a large Central Vacuole No vacuoles in bacterial cells copyright cmassengale

35 Chloroplasts Found in plants Photosynthesis – food making process Contains its own DNA Contains enzymes & pigments for Photosynthesis Never in animal or bacterial cells copyright cmassengale

36 Chloroplasts Surrounded by DOUBLE membrane Outer membrane smooth Inner membrane modified into sacs called Thylakoids Thylakoids in stacks called Grana & interconnected Stroma – gel like material surrounding thylakoids copyright cmassengale