www.denniskunkel.com Tour of the Cell Today’s Topics • Properties of all cells • Prokaryotes and Eukaryotes • Functions of Major Cellular Organelles – Information • Nucleus, Ribosomes – Synthesis&Transport • ER, Golgi, Vesicles – Energy Conversion • Mitochondria, Chloroplasts – Recycling • Lysosome, Peroxisome – Structure and Movement • Cytoskeleton and Motor Proteins • Cell Walls 9/16/11 1 www.denniskunkel.com Bacterial (Prokaryotic) Cell Common features of all cells • Plasma Membrane – defines inside from outside Ribosomes! Plasma membrane! • Cytosol Bacterial Cell wall! – Semifluid “inside” of the cell chromosome! 0.5 !m! • DNA “chromosomes” Flagella! - Genetic material – hereditary instructions No internal • Ribosomes membranes – “factories” to synthesize proteins 3 4 Figure 6.2b 1 cm Eukaryotic Cell Frog egg 1 mm Human egg 100 µm Most plant and animal cells 10 m µ Nucleus Most bacteria Light microscopy Mitochondrion 1 µm Super- 100 nm Smallest bacteria Viruses resolution microscopy Ribosomes 10 nm Electron microscopy Proteins Lipids 1 nm Small molecules Contains internal organelles 5 0.1 nm Atoms 1 endoplasmicENDOPLASMIC RETICULUM reticulum (ER) ENDOPLASMIC RETICULUM (ER) NUCLEUS NUCLEUS Rough ER Smooth ER nucleus Rough ER Smooth ER Nucleus Plasma membrane Plasma membrane Centrosome Centrosome cytoskeletonCYTOSKELETON CYTOSKELETON Microfilaments You should Microfilaments Intermediate filaments know everything Intermediate filaments Microtubules in Fig 6.9 ribosomesRibosomes Microtubules Ribosomes cytosol GolgiGolgi apparatus apparatus Golgi apparatus Peroxisome Peroxisome In animal cells but not plant cells: In animal cells but not plant cells: Lysosome Lysosomes Lysosome Lysosomes Figure 6.9 Centrioles Figure 6.9 Centrioles Mitochondrion lysosome Flagella (in some plant 7sperm) Mitochondrion Flagella (in some plant 8sperm) mitochondrion Nuclear envelope Nucleus Ribosomes Cytosol Nucleus 1 !m Nucleolus ER Free Ribosomes Make Cytoplasmic Chromatin Proteins Nuclear envelope: Inner membrane – Carry out protein synthesis Outer membrane Pores Membrane Bound Ribosomes Pore Make Proteins complex to be Exported Rough ER Surface of nuclear envelope. Ribosome 1 !m 0.25 !m Large subunit Close-up of nuclear envelope TEM showing ER and ribosomes 0.5 !m Figure 6.10 Small 9 10 Pore complexes (TEM). Nuclear lamina (TEM). subunit Figure 6.11 RNA & Protein Complex Diagram of a ribosome 1 Nucleus ENDOPLASMIC RETICULUM (ER) Nuclear envelope is connected to ER NUCLEUS EndoplasmicRough ER Smooth ER Reticulum Rough ER Plasma membrane Centrosome Smooth ER 2 transport vesicles CYTOSKELETON Microfilaments Intermediate filaments Golgi Microtubules Ribosomes Ribosomes 3 Golgi pinches off Transport Vesicles, Lysosomes, etc. GolgiGolgi apparatus apparatus Peroxisome In animal cells but not plant cells: Figure 6.9 Lysosome Lysosomes Figure 6.16 4 5 Plasma6 membrane expands Mitochondrion Centrioles 11 12 Flagella (in some plant sperm) by fusion of vesicles. 2 Rough ER Smooth ER Has attached ribosomes • Synthesis of – secreted proteins • Synthesis of – membrane proteins membrane lipids • Synthesizes steroids • Stores calcium • Detoxifies poison 13 14 Golgi Apparatus: protein secretion Processing, packaging and sorting center Cis Trans Golgi Golgi Adds Close Away oligosaccharides To Rough From ER Rough (glycosylation) ER 15 16 Mitochondria: NUCLEUS Powerhouses of the cell Mitochondria (and chloroplasts) Food -> ATP Figure 6.9 17 18 3 Chloroplasts capture ENDOPLASMIC RETICULUM (ER) energy from the sun Rough ER Smooth ER Chloroplast Photosynthesis Ribosomes Stroma Chloroplast Inner and outer DNA membranes Granum 1 !m Peroxisome Thylakoid Sunlight -> ATP, Sugar Figure 6.9 Lysosome 19 Lysosome (animals only) 20 Microtubules Microfilaments Intermediate ENDOPLASMIC RETICULUM (ER) Filaments Tubulin Actin NUCLEUS various 25 mM dia 7 mM dia Rough ER Smooth ER There are three 8-15 mM dia types of fibers that Cell shape Cell shape Nuclear Organelle movt Cell cleavage lamina make up the Chromosome Cytoplasmic Tension separation streaming bearing CytoskeletonCYTOSKELETON cytoskeleton Flagellar mvt Muscle contract elements Microfilaments Anchors Intermediate filaments Motors: Motors: Microtubules Dynein Myosin Kinesin Cytosol Figure 6.9 21 22 Table 6.1 Movement of Vesicles along Microtubules Vesicle ATP Receptor for motor protein Motor protein Microtubule (ATP powered) of cytoskeleton (a) Motor proteins that attach to receptors on organelles can “walk” the organelles along microtubules or, in some cases, microfilaments. Microtubule Vesicles 0.25 !m What evidence do we have that they actually move? (b) Vesicles containing neurotransmitters migrate to the tips of nerve cell axons via the mechanism in (a). In this SEM of a squid giant axon, two vesicles can be seen moving along a microtubule. (A separate part of the Figure 6.21 A, B experiment provided the evidence that they were in fact moving.) 23 24 4 Motor MAPs transport vesicles Three kinds of Movement • Filament anchored: motor “walks” along filament (transport vesicles) Dynein inbound • Motor anchored: filament moves (muscles) • Both anchored: bending (cilia and flagella) outbound MTOC kinesin 25 26 Fig. 6-24 Ribosomes (small brown dots) Outer microtubule Plasma 0.1 !m! doublet! membrane! Rough Dynein proteins! Plants have 2 other supportendoplasmic reticulum Smooth mechanismsNUCLEUS endoplasmic Central reticulum microtubules! Golgi apparatus Microtubules! Central vacuole/Tonoplast (b)!Cross section of • Cell Wall Plasma cilium! membrane! Basal body! • Vacuole or Microfilaments Intermediate CYTOSKELETON Tonoplast filaments 0.5 !m ! Microtubules (a)!Longitudinal 0.1 !m! section of cilium Mitochondrion ! Triplet! Cilia and Flagella Peroxisome Have 9+2 arrangement of microtubules Plasma membrane Chloroplast Cell wall and motor proteins. Wall of adjacent cell Plasmodesmata Figure 6.9 (c) Cross section of basal body! 27 28 Central Vacuoles (Tonoplasts) Extra Cellular Matrix – Only in plants glycoproteins Central vacuole Cytosol Acts like a “balloon in a box” to hold plant cells Tonoplast Nucleus Central rigid vacuole Cell wall Chloroplast Figure 6.15 29 30 5 !m 5 .