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Cell Biology ppt

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Chapter 4 Cell Biology

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Cell Biology ppt

  1. 1. Cell Structure and Function Chapter 4 Table of Contents Section 1 The History of Cell Biology Section 2 Introduction to Cells Section 3 Cell Organelles and Features Section 4 Unique Features of Plant Cells
  2. 2. Section 1 The History of Cell Biology Chapter 4 Objectives • Name the scientists who first observed living and nonliving cells. • Summarize the research that led to the development of the cell theory. • State the three principles of the cell theory. • Explain why the cell is considered to be the basic unit of life.
  3. 3. Section 1 The History of Cell Biology Chapter 4 The Discovery of Cells • All living things are made up of one or more cells. • A cell is the smallest unit that can carry on all of the processes of life.
  4. 4. Section 1 The History of Cell Biology Chapter 4 The Discovery of Cells, continued • Hooke – In 1665, Robert Hooke discovered cells in slices of cork. • Leeuwenhoek – In 1673, Anton van Leeuwenhoek was the first to observe living cells in microorganisms; Leeuwenhoek called these organism animalcules ~ we now call them protists.
  5. 5. Section 1 The History of Cell Biology Chapter 4 The Cell Theory • The cell theory states that all living organisms are made of one or more cells, cells are the basic units of structure and function, and cells come only from pre-existing cells. • In 1838, the German botanist Matthias Schleiden concluded that all plants were composed of cells • In 1839, Theodor Schwann concluded the same thing for animals • In 1855, Rudolf Virchow noted that all cells come from other cells
  6. 6. Chapter 4 Click below to watch the Visual Concept. Visual Concept Cell Theory Section 1 The History of Cell Biology
  7. 7. Section 1 The History of Cell Biology Chapter 4 The Cell Theory, continued • Cellular Basis of Life – All living things are made of organized parts, obtain energy from their surroundings, perform chemical reactions, change with time, respond to their environment, and reproduce.
  8. 8. Section 2 Introduction to Cells Chapter 4 Objectives • Explain the relationship between cell shape and cell function. • Identify the factor that limits cell size. • Describe the three basic parts of a cell. • Compare prokaryotic cells and eukaryotic cells. • Analyze the relationship among cells, tissues, organs, organ systems, and organisms.
  9. 9. Section 2 Introduction to Cells Chapter 4 Cell Diversity • Cell Shape – A cell’s shape reflects its function.
  10. 10. Section 2 Introduction to Cells Chapter 4 Cell Diversity, Continued • Cell Size – Cell size is limited by a cell’s surface area–to-volume ratio.
  11. 11. Chapter 4 Section 2 Introduction to Cells Cell size differs amongst species
  12. 12. Section 2 Introduction to Cells Chapter 4 Cell Size • Unicellular organisms are made up of one cell • Multicellular organisms are made up of many cells that often specialize according to function - differentiation
  13. 13. Section 2 Introduction to Cells Chapter 4 Specialized Animal Cells Bone Cells Cheek Cells Red Blood Cells
  14. 14. Chapter 4 Section 2 Introduction to Cells Prokaryotic Cells -Cells lack a nucleus and membrane-bound organelles -Includes bacteria -Single, circular chromosome in nucleoid region -Surrounded by cell membrane and a cell wall made up of peptidoglycan -Divided into two domains, I.e., Archaea and Bacteria
  15. 15. Eukaryotic Cells Section 2 Introduction to Cells Chapter 4 -Cells have a nucleus and membrane-bound organelles -Incudes protists, fungi, plants, and animals
  16. 16. Chapter 4 Section 2 Introduction to Cells Comparing Prokaryotes and Eukaryotes Click below to watch the Visual Concept. Visual Concept
  17. 17. Section 2 Introduction to Cells Chapter 4 Basic Parts of a Eukaryotic Cell • The three basic parts of a cell are the plasma membrane, the cytoplasm, and the nucleus.
  18. 18. Chapter 4 Section 2 Introduction to Cells Internal Organization of a Cell Click below to watch the Visual Concept. Visual Concept
  19. 19. Section 2 Introduction to Cells Chapter 4 Basic Parts of a Cell, continued • Plasma Membrane – The cell’s outer boundary, called the plasma membrane (or the cell membrane), covers a cell’s surface and acts as a barrier between the inside and the outside of a cell.
  20. 20. Section 2 Introduction to Cells Chapter 4 Basic Parts of a Cell, continued • Cytoplasm – The region of the cell that is within the plasma membrane and that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus is called the cytoplasm. – The part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane bound organelles is the cytosol – About 20% of the cytosol is made up of protein
  21. 21. Section 2 Introduction to Cells Chapter 4 Basic Parts of a Cell, continued • Nucleus – The nucleus is a membrane-bound organelle that contains a cell’s DNA.
  22. 22. Section 2 Introduction to Cells Chapter 4 Cellular Organization • In multicellular eukaryotes, cells organize into tissues, organs, organ systems, and finally organisms.
  23. 23. Chapter 4 Objectives Section 3 Cell Organelles and Features • Describe the structure and function of a cell’s plasma membrane. • Summarize the role of the nucleus. • List the major organelles found in the cytosol, and describe their roles. • Identify the characteristics of mitochondria. • Describe the structure and function of the cytoskeleton.
  24. 24. Chapter 4 Section 3 Cell Organelles and Features Plasma Membrane • Selectively permeable, separates internal metabolic reactions from the external environment, and allows cell to excrete waste • Membrane Lipids – Cell membranes consist of a phospholipid bilayer. – Phospholipids have a polar, hydrophilic (“water-loving”) phosphate head and two nonpolar, hydrophobic (“water-fearing”) fatty acid tails – Cholesterol gives membrane firmness and prevents freezing in low temperatures
  25. 25. Chapter 4 Structure of Lipid Bilayer Section 3 Cell Organelles and Features
  26. 26. Chapter 4 Section 3 Cell Organelles and Features Plasma Membrane, continued • Membrane Proteins – Cell membranes often contain proteins embedded within the phospholipid bilayer. – Proteins help move large molecules or aid in cell recognition (peripheral and integral)
  27. 27. Chapter 4 Section 3 Cell Organelles and Features Plasma Membrane, continued • Fluid Mosaic Model – The fluid mosaic model states that the phospholipid bilayer behaves like a fluid more than it behaves like a solid. – As a result of such lateral movement, the pattern, or “mosaic,” of lipids and proteins in the cellmembrane constantly changes
  28. 28. Chapter 4 Section 3 Cell Organelles and Features Nucleus • The nucleus directs the cell’s activities and stores DNA. • When a cell is not dividing, the DNA is in the form of a threadlike material called chromatin • When a cell is about to divide, the chromatin condenses to form chromosomes • Nuclear Envelope – The nucleus is surrounded by a double membrane called the nuclear envelope. • Nucleolus – The nucleolus is the place where DNA is concentrated when it is in the process of making ribosomal RNA.
  29. 29. Chapter 4 Section 3 Cell Organelles and Features Nucleus of a Cell
  30. 30. Chapter 4 Section 3 Cell Organelles and Features Mitochondria • Mitochondria harvest energy from organic compounds and transfer it to ATP. • Mitochondrial DNA – endosymbiotic origin
  31. 31. Chapter 4 Ribosomes Section 3 Cell Organelles and Features • Ribosomes are either free or attached to the rough ER and play a role in protein synthesis. • Made of protein an RNA molecules • Ribosome assembly begins in the nucleolus and is completed in the cytoplasm
  32. 32. Chapter 4 Click below to watch the Visual Concept. Visual Concept Ribosomes Section 3 Cell Organelles and Features
  33. 33. Chapter 4 Section 3 Cell Organelles and Features Endoplasmic Reticulum – intracellular highway • The rough ER prepares proteins for export or insertion into the cell membrane. – Most abundant in cells that produce large amounts of protein for export, such as digestive glands and antibody-producing cells • The smooth ER builds lipids, like cholesterol, and participates in detoxification of toxins. – In ovaries and testes, smooth ER produces estrogen and testosterone, respectively – In skeletal and heart muscle cells, smooth ER releases calcium, which stimulates contraction – Abundant in liver and kidneys for detoxification
  34. 34. Chapter 4 Section 3 Cell Organelles and Features Endoplasmic Reticulum (ER) and Ribosomes Click below to watch the Visual Concept. Visual Concept
  35. 35. Chapter 4 Golgi Apparatus Section 3 Cell Organelles and Features • The Golgi apparatus processes and packages proteins; proteins get address labels that direct them to other parts of the cell
  36. 36. Chapter 4 Vesicles Section 3 Cell Organelles and Features • Vesicles, including lysosomes (digestive enzymes) and peroxisomes (detoxification enzymes – liver and kidneys), are classified by their contents. • Lysosomes digest worn-out organelles in a process called autophagy; digestion of damaged or extra cells by the enzymes of their own lysosomes is called autolysis •Protein Synthesis –The rough ER, Golgi apparatus, and vesicles work together to transport proteins to their destinations inside and outside the cell.
  37. 37. Chapter 4 Section 3 Cell Organelles and Features Processing of Proteins
  38. 38. Chapter 4 Cytoskeleton Section 3 Cell Organelles and Features • The cytoskeleton is made of protein fibers that help cells move and maintain their shape. • The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.
  39. 39. Chapter 4 Click below to watch the Visual Concept. Visual Concept Cytoskeleton Section 3 Cell Organelles and Features
  40. 40. Chapter 4 Section 3 Cell Organelles and Features Cytoskeleton, continued • Cilia and Flagella – Cilia and flagella are hairlike structures that extend from the surface of the cell, where they assist in movement.
  41. 41. Chapter 4 Section 3 Cell Organelles and Features Structure of Cilia and Flagella Click below to watch the Visual Concept. Visual Concept
  42. 42. Chapter 4 Section 3 Cell Organelles and Features Cytoskeleton, continued • Centrioles – Centrioles consist of two short cylinders of microtubules at right angles to each other and are involved in cell division.
  43. 43. Chapter 4 Objectives Section 4 Unique Features of Plant Cells • List three structures that are present in plant cells but not in animal cells. • Compare the plasma membrane,the primary cell wall, and the secondary cell wall. • Explain the role of the central vacuole. • Describe the roles of plastids in the life of a plant. • Identify features that distinguish prokaryotes, eukaryotes, plant cells, and animal cells.
  44. 44. Chapter 4 Plant Cells • Plant cells have cell walls, central vacuoles, and plastids. Section 4 Unique Features of Plant Cells
  45. 45. Chapter 4 Cell Wall Section 4 Unique Features of Plant Cells • In plant cells, a rigid cell wall covers the cell membrane and provides support and protection.
  46. 46. Chapter 4 Section 4 Unique Features of Plant Cells Parts of a Cell Wall Click below to watch the Visual Concept. Visual Concept
  47. 47. Chapter 4 Central Vacuole Section 4 Unique Features of Plant Cells • Large central vacuoles store water, enzymes, and waste products and provide support for plant tissue.
  48. 48. Chapter 4 Plastids Section 4 Unique Features of Plant Cells • Plastids store starch and pigments. – Chloroplasts – use light energy to make carbohydrates from carbon dioxide and water; thylakoids contain green pigment chlorophyll that absorbs light energy – Chromoplasts – contain colorful pigments – Amyloplasts – store starch
  49. 49. Chapter 4 Section 4 Unique Features of Plant Cells Comparing Cells • Prokaryotes, animal cells, and plant cells can be distinguished from each other by their unique features.
  50. 50. Chapter 4 Section 4 Unique Features of Plant Cells Comparing Plant and Animal Cells

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