Table of ContentsSection 1 The History of Cell BiologySection 2 Introduction to CellsSection 3 Cell Organelles and FeaturesSection 4 Unique Features of Plant CellsCell Structure and FunctionChapter 4

ObjectivesName 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.Section 1 The History of Cell BiologyChapter 4

The Discovery of CellsAll 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.

Section 1 The History of Cell BiologyChapter 4

The Discovery of Cells, continuedHookeIn 1665, Robert Hooke discovered cells in slices of cork.

LeeuwenhoekIn 1673, Anton van Leeuwenhoek was the first to observe living cells in microorganisms; Leeuwenhoek called these organism animalcules ~ we now call them protists. Section 1 The History of Cell BiologyChapter 4

The Cell TheoryThe 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 cellsIn 1839, Theodor Schwann concluded the same thing for animalsIn 1855, Rudolf Virchow noted that all cells come from other cellsSection 1 The History of Cell BiologyChapter 4

Chapter 4

Click below to watch the Visual Concept.Visual ConceptCell TheorySection 1 The History of Cell Biology

The Cell Theory, continuedCellular Basis of LifeAll living things are made of organized parts, obtain energy from their surroundings, perform chemical reactions, change with time, respond to their environment, and reproduce.Section 1 The History of Cell BiologyChapter 4

Section 2 Introduction to CellsChapter 4ObjectivesExplain 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.

Section 2 Introduction to CellsChapter 4Cell DiversityCell ShapeA cells shape reflects its function.

Section 2 Introduction to CellsChapter 4Cell Diversity, ContinuedCell SizeCell size is limited by a cells surface areato-volume ratio.

Cell size differs amongst speciesChapter 4Section 2 Introduction to Cells

Cell SizeUnicellular organisms are made up of one cellMulticellular organisms are made up of many cells that often specialize according to function - differentiationSection 2 Introduction to CellsChapter 4

Specialized Animal CellsSection 2 Introduction to CellsChapter 4Bone CellsCheek CellsRed Blood Cells

Prokaryotic CellsChapter 4-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 peptidoglycanSection 2 Introduction to Cells-Divided into two domains, I.e., Archaea and Bacteria

Eukaryotic CellsSection 2 Introduction to CellsChapter 4-Cells have a nucleus and membrane-bound organelles-Incudes protists, fungi, plants, and animals

Chapter 4

Click below to watch the Visual Concept.Visual ConceptComparing Prokaryotes and EukaryotesSection 2 Introduction to Cells

Section 2 Introduction to CellsChapter 4Basic Parts of a Eukaryotic CellThe three basic parts of a cell are the plasma membrane, the cytoplasm, and the nucleus.

Chapter 4

Click below to watch the Visual Concept.Visual ConceptInternal Organization of a CellSection 2 Introduction to Cells

Section 2 Introduction to CellsChapter 4Basic Parts of a Cell, continuedPlasma MembraneThe cells outer boundary, called the plasma membrane (or the cell membrane), covers a cells surface and acts as a barrier between the inside and the outside of a cell.

Section 2 Introduction to CellsChapter 4Basic Parts of a Cell, continuedCytoplasmThe 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 cytosolAbout 20% of the cytosol is made up of protein

Section 2 Introduction to CellsChapter 4Basic Parts of a Cell, continuedNucleusThe nucleus is a membrane-bound organelle that contains a cells DNA.

Section 2 Introduction to CellsChapter 4Cellular OrganizationIn multicellular eukaryotes, cells organize into tissues, organs, organ systems, and finally organisms.

Chapter 4ObjectivesDescribe the structure and function of a cells 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.Section 3 Cell Organelles and Features

Chapter 4Plasma MembraneSelectively permeable, separates internal metabolic reactions from the external environment, and allows cell to excrete wasteMembrane LipidsCell membranes consist of a phospholipid bilayer.Phospholipids have a polar, hydrophilic (water-loving) phosphate head and two nonpolar, hydrophobic (water-fearing) fatty acid tailsCholesterol gives membrane firmness and prevents freezing in low temperaturesSection 3 Cell Organelles and Features

Structure of Lipid BilayerChapter 4Section 3 Cell Organelles and Features

Chapter 4Plasma Membrane, continuedMembrane ProteinsCell membranes often contain proteins embedded within the phospholipid bilayer.Proteins help move large molecules or aid in cell recognition (peripheral and integral)Section 3 Cell Organelles and Features

Chapter 4Plasma Membrane, continuedFluid Mosaic ModelThe 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 changesSection 3 Cell Organelles and Features

Chapter 4NucleusThe nucleus directs the cells activities and stores DNA.When a cell is not dividing, the DNA is in the form of a threadlike material called chromatinWhen a cell is about to divide, the chromatin condenses to form chromosomesNuclear EnvelopeThe nucleus is surrounded by a double membrane called the nuclear envelope.NucleolusThe nucleolus is the place where DNA is concentrated when it is in the process of making ribosomal RNA.

Section 3 Cell Organelles and Features

Chapter 4Nucleus of a CellSection 3 Cell Organelles and Features

Chapter 4MitochondriaMitochondria harvest energy from organic compounds and transfer it to ATP.Mitochondrial DNA endosymbiotic originSection 3 Cell Organelles and Features

Chapter 4RibosomesRibosomes are either free or attached to the rough ER and play a role in protein synthesis.Made of protein an RNA moleculesRibosome assembly begins in the nucleolus and is completed in the cytoplasmSection 3 Cell Organelles and Features

Chapter 4

Click below to watch the Visual Concept.Visual ConceptRibosomesSection 3 Cell Organelles and Features

Chapter 4Endoplasmic Reticulum intracellular highwayThe 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 cellsThe smooth ER builds lipids, like cholesterol, and participates in detoxification of toxins.In ovaries and testes, smooth ER produces estrogen and testosterone, respectivelyIn skeletal and heart muscle cells, smooth ER releases calcium, which stimulates contractionAbundant in liver and kidneys for detoxification

Section 3 Cell Organelles and Features

Chapter 4

Click below to watch the Visual Concept.Visual ConceptEndoplasmic Reticulum (ER) and RibosomesSection 3 Cell Organelles and Features

Chapter 4Golgi ApparatusThe Golgi apparatus processes and packages proteins; proteins get address labels that direct them to other parts of the cell

Section 3 Cell Organelles and Features

Chapter 4VesiclesVesicles, 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

Section 3 Cell Organelles and FeaturesProtein SynthesisThe rough ER, Golgi apparatus, and vesicles work together to transport proteins to their destinations inside and outside the cell.

Processing of ProteinsChapter 4Section 3 Cell Organelles and Features

Chapter 4CytoskeletonThe cytoskeleton is made of protein fibers that help cells move and maintain their shape.

The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.Section 3 Cell Organelles and Features

Chapter 4

Click below to watch the Visual Concept.Visual ConceptCytoskeletonSection 3 Cell Organelles and Features

Chapter 4Cytoskeleton, continuedCilia and FlagellaCilia and flagella are hairlike structures that extend from the surface of the cell, where they assist in movement.

Section 3 Cell Organelles and Features

Chapter 4

Click below to watch the Visual Concept.Visual ConceptStructure of Cilia and FlagellaSection 3 Cell Organelles and Features

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

Chapter 4ObjectivesList 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.Section 4 Unique Features of Plant Cells

Chapter 4Plant CellsPlant cells have cell walls, central vacuoles, and plastids.

Section 4 Unique Features of Plant Cells

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

Chapter 4

Click below to watch the Visual Concept.Visual ConceptParts of a Cell WallSection 4 Unique Features of Plant Cells

Chapter 4Central VacuoleLarge central vacuoles store water, enzymes, and waste products and provide support for plant tissue.Section 4 Unique Features of Plant Cells

Chapter 4PlastidsPlastids store starch and pigments. Chloroplasts use light energy to make carbohydrates from carbon dioxide and water; thylakoids contain green pigment chlorophyll that absorbs light energyChromoplasts contain colorful pigmentsAmyloplasts store starch

Section 4 Unique Features of Plant Cells

Chapter 4Comparing CellsProkaryotes, animal cells, and plant cells can be distinguished from each other by their unique features.Section 4 Unique Features of Plant Cells

Chapter 4Comparing Plant and Animal CellsSection 4 Unique Features of Plant Cells