www.denniskunkel.com Tour of the Cell www.denniskunkel.com Today s Topics Properties of all cells Prokaryotes and Eukaryotes Functions of Major Cellular Organelles Information, Synthesis&Transport,, Vesicles Energy Conversion Mitochondria, s Recycling, Structure and Movement Cytoskeleton and Motor Cell Walls 9/6/ Common features of all cells Plasma Membrane defines inside from outside Semifluid inside of the cell DNA chromosomes - Genetic material hereditary instructions factories to synthesize proteins Bacterial (Prokaryotic) Cell Bacterial chromosome!!! Cell wall! Flagella! No internal membranes 0.5!m! 4 Eukaryotic Cell Figure 6.2b cm mm Frog egg Contains internal organelles 5 00 µm 0 µm µm 00 nm 0 nm nm 0. nm Human egg Most plant and animal cells Most bacteria Smallest bacteria Viruses Lipids Small molecules Atoms Light microscopy Superresolution microscopy Electron microscopy
endoplasmic ENDOPLASMIC RETICULUM reticulum () nucleus cytoskeleton cytosol mitochondrion You should know everything in Fig 6.9 ribosomes lysosome Centrioles 7 Centrioles 8 Nuclear envelope Nucleolus Chromatin Nuclear envelope: Inner membrane Free Carry out protein synthesis Make Cytoplasmic Outer membrane Pores Pore complex Membrane Bound Make to be Exported Figure 6.0 Surface of nuclear envelope. 0.25!m Pore complexes (TEM). Ribosome Close-up of nuclear envelope Nuclear lamina (TEM). 9 Large subunit TEM showing and ribosomes 0.5!m Small subunit Figure 6. RNA & Protein Complex Diagram of a ribosome 0 Endoplasmic Reticulum Nuclear envelope is connected to 2 transport vesicles pinches off Transport Vesicles,, etc. Centrioles Figure 6.6 4 5 Plasma 6 membrane expands 2 by fusion of vesicles. 2
Has attached ribosomes Synthesis of membrane lipids Synthesizes steroids Stores calcium Detoxifies poison Synthesis of secreted proteins membrane proteins 4 Apparatus: protein secretion Processing, packaging and sorting center Adds oligosaccharides (glycosylation) Cis Close To Rough Trans Away From Rough 5 6 Mitochondria: Powerhouses of the cell Mitochondria (and chloroplasts) Food -> ATP 7 8
s capture energy from the sun Photosynthesis DNA Stroma Inner and outer membranes Granum Thylakoid Sunlight -> ATP, Sugar 9 (animals only) 20 Cytoskeleton There are three types of fibers that make up the cytoskeleton Intermediate Filaments Tubulin Actin various 25 mm dia 7 mm dia 8-5 mm dia Cell shape Organelle movt Chromosome separation Flagellar mvt Motors: Dynein Kinesin Cell shape Cell cleavage Cytoplasmic streaming Muscle contract Motors: Myosin Nuclear lamina Tension bearing elements Anchors 2 22 Table 6. Movement of Vesicles along ATP Vesicle 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? Figure 6.2 A, B (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 experiment provided the evidence that they were in fact moving.) 2 24 4
Three kinds of Movement Motor MAPs transport vesicles Filament anchored: motor walks along filament (transport vesicles) Motor anchored: filament moves (muscles) Dynein inbound Both anchored: bending (cilia and flagella) outbound kinesin MTOC 25 26 Fig. 6-24! Plasma membrane! Basal body! 0.5!m! (a)!longitudinal section of cilium! 0.! (b)!cross section of cilium! 0.! Triplet! Cilia and Flagella (c) Cross section of basal body! Outer microtubule doublet! Dynein proteins! Central microtubules! Have 9+2 arrangement of microtubules and motor proteins. Plasma membrane! 27 (small brown dots) Plants have 2 other support mechanisms Cell Wall Vacuole or Tonoplast Cell wall Wall of adjacent cell Rough endoplasmic reticulum Smooth endoplasmic reticulum Central vacuole/tonoplast Intermediate filaments Plasmodesmata 28 Central Vacuoles (Tonoplasts) Only in plants Extra Cellular Matrix glycoproteins Central vacuole Acts like a balloon in a box to hold plant cells rigid Tonoplast Central vacuole Cell wall Figure 6.5 29 5!m 0 5