Transcript Outline 7
7-2 Eukaryotic Cell Structure Slide 1 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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. Slide 2 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Eukaryotic Cell Structures Animal Cell Nucleolus Smooth endoplasmic reticulum Nucleus Ribosome (free) Nuclear envelope Cell membrane Rough endoplasmic reticulum Ribosome (attached) Centrioles Golgi apparatus Mitochondrion Slide 3 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Eukaryotic Cell Structures Plant Cell Nucleolus Nucleus Smooth endoplasmic reticulum Nuclear envelope Ribosome (free) Rough endoplasmic reticulum Ribosome (attached) Golgi apparatus Cell wall Cell membrane Chloroplast Mitochondrion Vacuole Slide 4 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Copyright Pearson Prentice Hall Slide 5 of 49 End Show 7-2 Eukaryotic Cell Structure Nucleus The Nucleus Chromatin Nuclear envelope Nucleolus Nuclear pores Slide 6 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Eukaryotic Cell Structures B. Ribosomes 1. Small particles composed of RNA & protein 2. Found throughout the cytoplasm 3. Help to produce protein Slide 7 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 8 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 9 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Endoplasmic Reticulum Rough Endoplasmic Reticulum Ribosomes Slide 10 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 11 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Endoplasmic Reticulum Smooth Endoplasmic Reticulum Slide 12 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 13 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Golgi Apparatus Golgi Apparatus Slide 14 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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. Slide 15 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 16 of 49 pump out excess water from cells Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Vacuoles Plant Cell Paramecium Central Vacuole Contractile vacuole Slide 17 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Copyright Pearson Prentice Hall Slide 18 of 49 End Show 7-2 Eukaryotic Cell Structure 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 Slide 19 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Copyright Pearson Prentice Hall Slide 20 of 49 End Show 7-2 Eukaryotic Cell Structure Vacuoles Slide 21 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 22 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure Cytoskeleton Cytoskeleton Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Copyright Pearson Prentice Hall Slide 23 of 49 End Show 7-2 Eukaryotic Cell Structure 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. Slide 24 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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 Slide 25 of 49 Copyright Pearson Prentice Hall End Show 7-2 Eukaryotic Cell Structure 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. Slide 26 of 49 Copyright Pearson Prentice Hall End Show