1. BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 4 A Tour of the Cell Modules 4.15 – 4.21

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chloroplasts are found in plants and some protists Chloroplasts convert solar energy to chemical energy in sugars Capturing of light and electron enregizing occur in the grana and chemical reactions forming food storage molecules occur in the stroma. 4.15 Chloroplasts convert solar energy to chemical energy ENERGY-CONVERTING ORGANELLES Chloroplast Stroma Inner and outer membranes Granum Intermembrane space Figure 4.15

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Mitochondria carry out cellular respiration –This process uses the chemical energy in food to make ATP for cellular work –ATP is the energy storage molecule. –Cellular respiration takes place in the presence of oxygen. –Carbon dioxide and water are given off by the cell during the oxidation of glucose. –ATP is produced for the cells energy needs 4.16 Mitochondria harvest chemical energy from food

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.16 Outer membrane MITOCHONDRION Intermembrane space Inner membrane Cristae Matrix

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A network of protein fibers makes up the cytoskeleton 4.17 The cell’s internal skeleton helps organize its structure and activities THE CYTOSKELETON AND RELATED STRUCTURES Figure 4.17A

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings MICROFILAMENT Figure 4.17B INTERMEDIATE FILAMENT MICROTUBULE Actin subunitFibrous subunits Tubulin subunit 7 nm10 nm 25 nm

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Microfilaments of actin enable cells to change shape and move Intermediate filaments reinforce the cell and anchor certain organelles Microtubules –give the cell rigidity –provide anchors for organelles –act as tracks for organelle movement

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A microfilament of actin is a globular structural protein that polymerizes in a helical fashion. These form the cytoskeleton - a three-dimensional network inside an eukaryotic cell. Actin filaments provide mechanical support for the cell, determine the cell shape, enable cell movements (through lamellipodia, filopodia, or pseudopodia); and participate in certain cell junctions, in cytoplasmic streaming and in contraction of the cell during cytokinesis..protein polymerizescytoskeletoneukaryoticcelllamellipodia filopodiapseudopodiacell junctionscytoplasmic streamingcytokinesis

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The microfilaments are the thinnest component of the cytoskeleton, measuring only 5 nm in diameter.nmdiameter Actin is one of the most abundant proteins in many eukaryotic cells, with concentrations of over 100 μM. It is also one of the most highly conserved proteins, differing by no more than 5% in species as diverse as algae and humans.conservedspeciesalgae humans

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Intermediate filaments (IFs) are cytoskeletal structures formed by members of a family of related proteins. Intermediate filaments have a diameter between that of actin (microfilaments) and microtubules. Most types of intermediate filaments are located in the cytosol between the nuclear envelope and the cell surface membrane. Nuclear lamins are localized to the cell nucleus.cytoskeletal actinmicrofilamentsmicrotubulescytosolnuclear envelopecell surface membrane Nuclear lamins

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings There are about 70 different genes coding for various intermediate filament proteins. However, different kinds of IFs share basic characteristics: they are all polymers that generally measure between 9-11 nm in diameter when fully assembled

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Microtubules are protein structures found within cells, one of the components of the cytoskeleton. They have diameter of ~ 24 nm and length varying from several micrometers to possibly millimeters in axons of nerve cells. Microtubules serve as structural components within cells and are involved in many cellular processes including mitosis, cytokinesis, and vesicular transport. Microtubules are polymers of α- and β-tubulin dimersproteincellscytoskeletonnm mitosiscytokinesisvesicular transporttubulindimers

13. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Eukaryotic cilia and flagella are locomotor appendages that protrude from certain cells A cilia or flagellum is composed of a core of microtubules wrapped in an extension of the plasma membrane These structures are often associated with many mitochondria. 4.18 Cilia and flagella move when microtubules bend

14. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.18A FLAGELLUM Outer microtubule doublet Plasma membrane Central microtubules Outer microtubule doublet Plasma membrane Electron micrograph of sections: Flagellum Basal body Basal body (structurally identical to centriole)

15. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Clusters of microtubules drive the whipping action of these organelles Figure 4.18B Microtubule doublet Dynein arm Sliding force

16. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells interact with their environments and each other via their surfaces Plant cells are supported by rigid cell walls made largely of cellulose –They connect by plasmodesmata, channels that allow them to share water, food, and chemical messages 4.19 Cell surfaces protect, support, and join cells EUKARYOTIC CELL SURFACES AND JUNCTIONS

17. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.19A Vacuole Layers of one plant cell wall Walls of two adjacent plant cells PLASMODESMATA Cytoplasm Plasma membrane

18. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Animal cells are embedded in an extracellular matrix of predominantly collagens. –It is a sticky layer of glycoproteins –It binds cells together in tissues like the mortar of a brick wall. –It can also provide a way of separating the tissues, and regulating intercellular communication –It can also have protective functions

19. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Tight junctions can bind cells together into leakproof sheets. For this reason they are more superficial. Anchoring junctions link animal cells Communicating junctions allow substances to flow from cell to cell TIGHT JUNCTION ANCHORING JUNCTION COMMUNICATING JUNCTION Plasma membranes of adjacent cells Extracellular matrix Figure 4.19B

20. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Eukaryotic organelles fall into four functional groups 4.20 Eukaryotic organelles comprise four functional categories Table 4.20

21. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 4.20 (continued)

22. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cell types and Their Morphology At all levels of organization, biological structures are shaped by natural selection to maximize their ability to perform their functions. Many cells have a structure that suits their function in the body. There are about 210 different cell types in the human body.

23. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The eye

24. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The rods and cones of the retina SEM or TEM?

25. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Columnar Epithelium such as that found in the intestine. > Surface area

26. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The Nerve Cell

27. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Muscle cell

28. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

29. BLOOD Cells

30. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 2-4 pages …. Due December 14 th or 15th Choose one organelle or cellular body and discuss a disease which results if that structure is not functioning properly. OR Choose a cell type and explain how its structure is suited for its function. References needed