1. Chapter 4 Table of Contents Section 1 The History of Cell Biology
Cell Structure and Function
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. 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. Chapter 4 The Discovery of Cells
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. The Discovery of Cells, continued
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. Chapter 4 The Cell Theory
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. Chapter 4 Cell Theory Section 1 The History of Cell Biology
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Visual Concept

7. The Cell Theory, continued
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. 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. Chapter 4 Cell Diversity Cell Shape
Section 2 Introduction to Cells
Chapter 4
Cell Diversity
Cell Shape
A cell’s shape reflects its function.

10. Cell Diversity, Continued
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. Cell size differs amongst species
Section 2 Introduction to Cells
Chapter 4
Cell size differs amongst species

12. Chapter 4 Cell Size Unicellular organisms are made up of one cell
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. Specialized Animal Cells
Section 2 Introduction to Cells
Chapter 4
Specialized Animal Cells
Red Blood Cells
Cheek Cells
Bone Cells

14. Chapter 4 Prokaryotic Cells
Section 2 Introduction to Cells
Chapter 4
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. -Cells have a nucleus and membrane-bound organelles
Section 2 Introduction to Cells
Chapter 4
Eukaryotic Cells
-Cells have a nucleus and membrane-bound organelles
-Incudes protists, fungi, plants, and animals

16. Comparing Prokaryotes and Eukaryotes
Section 2 Introduction to Cells
Chapter 4
Comparing Prokaryotes and Eukaryotes
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Visual Concept

17. Basic Parts of a Eukaryotic Cell
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. Internal Organization of a Cell
Section 2 Introduction to Cells
Chapter 4
Internal Organization of a Cell
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Visual Concept

19. Basic Parts of a Cell, continued
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. Basic Parts of a Cell, continued
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. Basic Parts of a Cell, continued
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. Cellular Organization
Section 2 Introduction to Cells
Chapter 4
Cellular Organization
In multicellular eukaryotes, cells organize into tissues, organs, organ systems, and finally organisms.

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. Chapter 4 Plasma Membrane
Section 3 Cell Organelles and Features
Chapter 4
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. Structure of Lipid Bilayer
Section 3 Cell Organelles and Features
Chapter 4
Structure of Lipid Bilayer

26. Plasma Membrane, continued
Section 3 Cell Organelles and Features
Chapter 4
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. Plasma Membrane, continued
Section 3 Cell Organelles and Features
Chapter 4
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. Section 3 Cell Organelles and Features
Chapter 4
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. Section 3 Cell Organelles and Features
Chapter 4
Nucleus of a Cell

30. Section 3 Cell Organelles and Features
Chapter 4
Mitochondria
Mitochondria harvest energy from organic compounds and transfer it to ATP.
Mitochondrial DNA – endosymbiotic origin

31. Section 3 Cell Organelles and Features
Chapter 4
Ribosomes
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. Chapter 4 Ribosomes Section 3 Cell Organelles and Features
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Visual Concept

33. Endoplasmic Reticulum – intracellular highway
Section 3 Cell Organelles and Features
Chapter 4
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. Endoplasmic Reticulum (ER) and Ribosomes
Section 3 Cell Organelles and Features
Chapter 4
Endoplasmic Reticulum (ER) and Ribosomes
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Visual Concept

35. Chapter 4 Golgi Apparatus
Section 3 Cell Organelles and Features
Chapter 4
Golgi Apparatus
The Golgi apparatus processes and packages proteins; proteins get address labels that direct them to other parts of the cell

36. Section 3 Cell Organelles and Features
Chapter 4
Vesicles
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. Processing of Proteins
Section 3 Cell Organelles and Features
Chapter 4
Processing of Proteins

38. Section 3 Cell Organelles and Features
Chapter 4
Cytoskeleton
The cytoskeleton is made of protein fibers that help cells move and maintain their shape.
The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.

39. Chapter 4 Cytoskeleton Section 3 Cell Organelles and Features
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Visual Concept

40. Cytoskeleton, continued
Section 3 Cell Organelles and Features
Chapter 4
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. Structure of Cilia and Flagella
Section 3 Cell Organelles and Features
Chapter 4
Structure of Cilia and Flagella
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Visual Concept

42. Cytoskeleton, continued
Section 3 Cell Organelles and Features
Chapter 4
Cytoskeleton, continued
Centrioles
Centrioles consist of two short cylinders of microtubules at right angles to each other and are involved in cell division.

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. Section 4 Unique Features of Plant Cells
Chapter 4
Plant Cells
Plant cells have cell walls, central vacuoles, and plastids.

45. Section 4 Unique Features of Plant Cells
Chapter 4
Cell Wall
In plant cells, a rigid cell wall covers the cell membrane and provides support and protection.

46. Chapter 4 Parts of a Cell Wall
Section 4 Unique Features of Plant Cells
Chapter 4
Parts of a Cell Wall
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47. Chapter 4 Central Vacuole
Section 4 Unique Features of Plant Cells
Chapter 4
Central Vacuole
Large central vacuoles store water, enzymes, and waste products and provide support for plant tissue.

48. Chapter 4 Plastids Plastids store starch and pigments.
Section 4 Unique Features of Plant Cells
Chapter 4
Plastids
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. Chapter 4 Comparing Cells
Section 4 Unique Features of Plant Cells
Chapter 4
Comparing Cells
Prokaryotes, animal cells, and plant cells can be distinguished from each other by their unique features.

50. Comparing Plant and Animal Cells
Section 4 Unique Features of Plant Cells
Chapter 4
Comparing Plant and Animal Cells