1. End Show Slide 1 of 49 Copyright Pearson Prentice Hall 7-2 Eukaryotic Cell Structure

2. End Show 7-2 Eukaryotic Cell Structure Slide 2 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures I. Eukaryotic Cell Structures A. Cell Parts – 3 main parts: 1. Cell membrane - outside boundary. Regulates what enters & leaves a cell. 2. Organelles - structures that perform important cellular functions. Many enclosed by membranes. 3. Cytoplasm – gel-like portion of the cell that surrounds the organelles.

3. End Show 7-2 Eukaryotic Cell Structure Slide 3 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures Smooth endoplasmic reticulum Ribosome (free) Ribosome (attached) Golgi apparatus Mitochondrion Rough endoplasmic reticulum Cell membrane Nucleus Nuclear envelope Nucleolus Centrioles Animal Cell

4. End Show 7-2 Eukaryotic Cell Structure Slide 4 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures Plant Cell Nuclear envelope Ribosome (free) Ribosome (attached) Mitochondrion Golgi apparatus Vacuole Nucleolus Nucleus Smooth endoplasmic reticulum Rough endoplasmic reticulum Cell wall Cell membrane Chloroplast

5. End Show 7-2 Eukaryotic Cell Structure Slide 5 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures II. Eukaryotic Organelles A. Nucleus 1. Control center of the cell 2. Nuclear envelope a. Double membrane around nucleus 3. Nuclear pores a. Small channels that allow substances to move in & out of nucleus 4. Nucleolus a. Where ribosomes are made

6. End Show 7-2 Eukaryotic Cell Structure Slide 6 of 49 Copyright Pearson Prentice Hall Nucleus The Nucleus Nucleolus Nuclear envelope Nuclear pores Chromatin

7. End Show 7-2 Eukaryotic Cell Structure Slide 7 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures B. Ribosomes 1. Small particles composed of RNA & protein 2. Found throughout the cytoplasm 3. Help to produce protein

8. End Show 7-2 Eukaryotic Cell Structure Slide 8 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures C. Endoplasmic Reticulum (ER) 1. Extensive internal membrane system 2. Moves proteins and other substances throughout the cell 3. Two types of ER: a. Rough ER – has ribosomes b. Smooth ER – no ribosomes

9. End Show 7-2 Eukaryotic Cell Structure Slide 9 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures 4. Rough ER a. Protein made on ribosomes b. Enters rough ER c. Protein travels through ER d. Portion of ER pinches off to form a vesicle: ♣ Small membrane-bound sac that transports substances e. These proteins will usually be exported from the cell

10. End Show 7-2 Eukaryotic Cell Structure Slide 10 of 49 Copyright Pearson Prentice Hall Endoplasmic Reticulum Ribosomes Rough Endoplasmic Reticulum

11. End Show 7-2 Eukaryotic Cell Structure Slide 11 of 49 Copyright Pearson Prentice Hall Eukaryotic Cell Structures 5. Smooth ER a. Does not have ribosomes b. Contains collections of enzymes that perform specialized tasks such as: ♣ Synthesis of cell membrane lipids ♣ Detoxification of drugs

12. End Show 7-2 Eukaryotic Cell Structure Slide 12 of 49 Copyright Pearson Prentice Hall Endoplasmic Reticulum Smooth Endoplasmic Reticulum

13. End Show 7-2 Eukaryotic Cell Structure Slide 13 of 49 Copyright Pearson Prentice Hall Golgi Apparatus D. Golgi Apparatus 1. Vesicles full of proteins produced in rough ER move into Golgi apparatus. 2. Golgi appears as a stack of flattened, membrane-bound sacs 3. Function: a. Modifies, sorts, and packages proteins b. Modified proteins then enclosed in new vesicles which bud off and are shipped to final destinations inside or outside of cell

14. End Show 7-2 Eukaryotic Cell Structure Slide 14 of 49 Copyright Pearson Prentice Hall Golgi Apparatus

15. End Show 7-2 Eukaryotic Cell Structure Slide 15 of 49 Copyright Pearson Prentice Hall Lysosomes E. Lysosomes 1. Small membrane-bound organelles filled with enzymes. 2. Break down lipids, carbohydrates, & proteins into small molecules 3. Also break down organelles that have outlived their usefulness.

16. End Show 7-2 Eukaryotic Cell Structure Slide 16 of 49 Copyright Pearson Prentice Hall Vacuoles F. Vacuoles 1. Saclike structures that store materials such as water, salts, proteins, and carbohydrates. 2. In plant cells there is a single, large central vacuole filled with liquid. a. Water pressure in vacuole allows plants to stand up. 3. Small vacuoles are found in unicellular organisms and some animals. a. Contractile vacuoles in Paramecium help pump out excess water from cells

17. End Show 7-2 Eukaryotic Cell Structure Slide 17 of 49 Copyright Pearson Prentice Hall Vacuoles Central Vacuole Paramecium Contractile vacuole Plant Cell

18. End Show 7-2 Eukaryotic Cell Structure Slide 18 of 49 Copyright Pearson Prentice Hall Vacuoles G. Mitochondria 1. Organelles that convert chemical energy in food into forms of energy that the cell can use more easily (ATP). a. Cells with high energy requirements, like muscles, have many mitochondria 2. Have two membranes: a. Smooth outer membrane b. Inner is highly folded up inside

19. End Show 7-2 Eukaryotic Cell Structure Slide 19 of 49 Copyright Pearson Prentice Hall Mitochondria and Chloroplasts 3. Mitochondria have their own DNA and ribosomes a. Can make their own proteins b. Endosymbiosis: theory that mitochondria evolved from primitive prokaryotes

20. End Show 7-2 Eukaryotic Cell Structure Slide 20 of 49 Copyright Pearson Prentice Hall Vacuoles H. Chloroplasts 1. Plant organelles that capture sunlight energy and convert it into chemical energy of carbohydrates a. This process is called photosynthesis b. Sunlight is absorbed by the green pigment chlorophyll 2. Have two membranes: a. Inner & outer 3. Also have own DNA & ribosomes & probably descended from prokaryotes

21. End Show 7-2 Eukaryotic Cell Structure Slide 21 of 49 Copyright Pearson Prentice Hall Vacuoles

22. End Show 7-2 Eukaryotic Cell Structure Slide 22 of 49 Copyright Pearson Prentice Hall Cytoskeleton I. Cytoskeleton 1. Eukaryotic cells are given their shape and internal organization by the cytoskeleton. 2. This is also involved in movement 3. Made up of: a. Microfilaments b. Microtubules

23. End Show 7-2 Eukaryotic Cell Structure Slide 23 of 49 Copyright Pearson Prentice Hall Cytoskeleton Ribosomes Mitochondrion Endoplasmic reticulum Cell membrane Microtubule Microfilament

24. End Show 7-2 Eukaryotic Cell Structure Slide 24 of 49 Copyright Pearson Prentice Hall Cytoskeleton 4. Microfilaments a. Threadlike structures made of protein actin. b. Form extensive networks in some cells. c. Produce tough, flexible framework that supports the cell. d. Help some cells move.

25. End Show 7-2 Eukaryotic Cell Structure Slide 25 of 49 Copyright Pearson Prentice Hall Cytoskeleton 5. Microtubules a. Hollow structures made of proteins known as tubulins b. Maintain cell shape c. Are important in cell division d. Build projections from the cell surface— cilia and flagella—that enable some cells to swim

26. End Show 7-2 Eukaryotic Cell Structure Slide 26 of 49 Copyright Pearson Prentice Hall Cytoskeleton e. In animal cells, structures known as centrioles are formed from tubulin. ● These are located near the nucleus and help to organize cell division.