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Cell theory and structure

Cell theory and structure SWBAT: Describe various structures and functions of organelles within a cell by participating in a class discussion. SWBAT: Identify cell organelles and their functions within the cell. 1/28: Why does a cell need organelles (little organs)?

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Cell theory and structure

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  1. Cell theory and structure SWBAT: Describe various structures and functions of organelles within a cell by participating in a class discussion. SWBAT: Identify cell organelles and their functions within the cell. 1/28:Why does a cell need organelles (little organs)? E?: How do organelles work together in a cell?

  2. Cell Structure and Organelle Function

  3. Explain: Cell Diversity • Cells within the same organism show Enormous Diversity in: • Size • Shape • Internal Organization

  4. 1. Cell Size • Female Egg - largest cell in the human body; seen without the aid of a microscope • Most cells are visible only with a microscope.

  5. Cells are small for 2 Reasons Reason 1: • Limited in size by the RATIO between their Outer Surface Area and Their Volume.  A small cell has more SURFACE AREA than a large cell for a GIVEN VOLUME OF CYTOPLASM. 

  6. Cells are Small Reason 2: • THE CELL'S NUCLEUS CAN ONLY CONTROL A CERTAIN AMOUNT OF LIVING, ACTIVE CYTOPLASM.

  7. 2. Cell Shape • Diversity of form reflects a diversity of function. • THE SHAPE OF A CELL DEPENDS ON ITS FUNCTION.

  8. Cell membrane Cytoplasm Cell membrane Cytoplasm 3. Internal Organization Prokaryotic Cell Eukaryotic Cell Nucleus Organelles

  9. Prokaryotic Examples ONLY Bacteria & Archaea

  10. EUKARYOTIC CELLS Two Kinds: Plant and Animal

  11. Eukaryotic Example Animal Cell

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

  13. Animal Cells Plant Cells Cell Wall Chloroplasts Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Centrioles Compare and Contrast Vacuoles: Many/Small Vacuoles: Few/Large

  14. Internal Organization • Cells contain ORGANELLES. • Cell Components that PERFORMS SPECIFIC FUNCTIONS FOR THE CELL.

  15. CELL MEMBRANE (plasma membrane) • Made up of lipids (fats) and proteins • Selective permeable membrane with a hydrophilic heads and hydrophobic tail 2. Three main jobs • protect the cell from its surroundings • support the cell and give it shape • control passage in and out of the cell (selective permeable) 3. Plants also have cell wall • reason why plants don't need a skeleton

  16. Cellular Organelles • The Plasma membrane • The boundary of the cell. • Composed of three distinct layers. • Two layers of fat and one layer of protein.

  17. Cell Wall • Extra structure surrounding its plasma membrane in plants, algae, fungi, and bacteria. • Cellulose – Plants • Chitin – Fungi • Peptidoglycan - Bacteria

  18. Tomorrow! • Candy Cell Lab! • Must include a legend of which candy is what organelle and a brief explanation of the function • Best behavior • FOLLOW INSTRUCTIONS • Power point is on DoBosh’s resource page • at the FUSD website under teacher, his name, and resources

  19. The Nucleus • Brain of Cell • Bordered by a porous membrane - nuclear envelope. • Contains thin fibers of DNA and protein called Chromatin. • Rod Shaped Chromosomes • Contains a small round nucleolus • produces ribosomal RNA which makes ribosomes.

  20. NUCLEUS • On a stained cell, the nucleus is the dark, round structure, usually near the middle of the cell. • Control center of the cell • controls activity of cell • controls heredity of cell (DNA) • Separated from the rest of the cell by the nuclear membrane • Protects nucleus • Contains the nucleolus (nucleoli) • small round structures within nucleus • help make information organelles called ribosomes • makes RNA • Also contains chromatin - hereditary material (DNA) • Some cells (like bacteria) do not have a separate nucleus -instead, the DNA floats around. (PROKARYOTES) • EUKARYOTES -have a distinct nucleus surrounded by nuclear membrane

  21. CYTOPLASM a. All the living substance in a cell except the nucleus b. The gel-like substance where the organelles are suspended c. Most life processes occur here d. Contains the organelles ("little organs" which have special jobs to do - they work together to keep the cell working properly)

  22. Mitochondrion • Double Membranous • It’s the size of a bacterium • Contains its own DNA; mDNA • Produces high energy compound ATP

  23. Examples of Organelles • mitochondrion (mitochondria) a. small, rod-shaped structures b. break down glucose to provide cell with energy (ATP - this is called cellular respiration) c. the powerhouse of the cell – the Mighty Mitochondria! d. cells that need a lot of energy have a lot of these (muscles, root tips)

  24. Endoplasmic Reticulum • Complex network of transport channels. • Two types: • Smooth- ribosome free and functions in poison detoxification. (Lickerish) • Rough - contains ribosomes and releases newly made protein from the cell. (Nerds Rope)

  25. Endoplasmic Reticulum (ER) • System of membranous tubes and sacs called cisternae • Functions as an intercellular highway – a path along which molecules move from one part of the cell to another. • Amount of ER inside a cell fluctuates depending on cell activity

  26. Types of ER (continuous interconnected network) • Rough ER: covered with ribosomes. • Produces phospholipids and proteins. • Certain types of proteins are made on the rough ER’s ribosomes which are later exported outside of the cell or inserted into one of the cell’s own membranes • Ex. Rough ER ribosomes make digestive enzymes which accumulate inside the ER. Little sacs or vesicles pinch off from the ends of rough ER and store the digestive enzymes until they are released from the cell • Most abundant

  27. Smooth ER: not covered with ribosomes • Not abundant • Builds lipids such as cholesterol • In ovaries and testes produces steroid hormones – estrogen and testosterone • Releases calcium in skeletal and heart muscle cells to stimulate contraction • Helps detoxify drugs and poisons in kidneys and liver. Long-term abuse of alcohol and other drugs causes these cells to produce more smooth ER. Can lead to drug tolerance

  28. More Examples… • microtubule (cytoskeleton) a. Tubes and filaments b. important in cell movement c. skeleton of cell d. Throughout cell 3. endoplasmic reticulum (ER) a. Complex network of sacs b. moves substances from one organelle to another c. highway system of cell - provides site for different functions of cell (miniature circulatory system of cell) d. rough or smooth - with or without ribosomes

  29. Golgi Apparatus • A series of flattened sacs that modifies, packages, stores, and transports materials out of the cell. • Works with the ribosomes and Endoplasmic Reticulum.

  30. More Examples… 4. Ribosomes • small round structures b. where cells synthesize (make) proteins c. Either floating free or on ER 5. Vacuoles a. liquid-filled spaces surrounded by membranes b. store substances used by cells and store wastes c. Holes d. Throughout cell 6. Lysosome • special kind of vacuole – usually small b. digest large food particles c. stomach of cell - garbage disposal d. Plant cells don’t have them

  31. Ribosomes • Small non-membrane bound organelles. • Contain two sub units • Site of protein synthesis. • Protein factory of the cell • Either free floating or attached to the Endoplasmic Reticulum.

  32. The Vacuole • Sacs that help in food digestion or helping the cell maintain its water balance. • Found mostly in plants and protists. • Animals many/small • Plants fewer/large • Make up 50 – 70 % of the cell

  33. Food vacuoles: vesicles that store nutrients for a cell • Contractile vacuoles: vesicles that contract and dispose of excess water

  34. Lysosomes • Recycling Center • Recycle cellular debris • Membrane bound organelle containing a variety of enzymes. • Internal pH is 5. • Help digest food particles inside or out side the cell.

  35. The Chloroplast • Double membrane • Center section contains grana • Thylakoid (coins) make up the grana. • Stroma - gel-like material surrounding grana • Found in plants and algae.

  36. More Examples… 7. Golgi bodies a. look like a stack of pancakes b. package cell secretions and modifies them for distribution c. Throughout cell • Centriole a. small, cylindrical bodies b. important in mitosis (cell reproduction) c. found only in animal cells during certain phases of mitosis • Chloroplasts a. larger, oval shaped, green b. photosynthesis occurs here c. found only in plants

  37. Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Cytoskeleton

  38. Centrioles • Found only in animal cells • Paired organelles found together near the nucleus, at right angles to each other. • Role in building cilia and flagella • Play a role in cellular reproduction

  39. Vesicles • Transport substances into and out of cells • Often produced in the Golgi = a packaged protein

  40. Other Structures sometimes found: • Flagella • a whip-like tail that allows locomotion for a cell • Example: human sperm • Cilia a. cover the cell b. example: found in your respiratory tract

  41. Eukaryotic 1. Contains a nucleus and other membrane bound organelles. 2. Rod shaped chromosomes 3. Found in all kingdoms except the Eubacteria and Archaebacteria Prokaryotic Does not contain a nucleus or other membrane bound organelles. Circular chromosome Found only in the Eubacteria and Archaebacteria Kingdoms Cell Types (Review)

  42. Plant Cells vs. Animal Cells - differences 1. Plant cells have: • chloroplasts • cell walls • one or two large vacuoles - 50% of volume of cell 2. Animal cells have: • no cell walls • Centriole • many small vacuoles

  43. Drum roll please! • Eat your donut!!!!!!!!!!!!!!!!!!!!!

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