copyright © 2003 pearson education, inc. publishing as benjamin cummings wassily kandinsky...
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Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Wassily Kandinsky (1866-1944)
Cells
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Figure 4.1x
Cell Theory:
- all organisms are composed of cells
- all cells come from other cells
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• Scanning electron microscope (SEM)
Figure 4.1B
TEM
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• Cell size and shape relate to function
• Minimum
• Maximum
Figure 4.2
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• A small cell has a greater ratio of surface area to volume than a large cell of the same shape
30 µm 10 µm
Surface areaof one large cube= 5,400 µm2
Total surface areaof 27 small cubes= 16,200 µm2Figure 4.3
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• Prokaryotic cells - “before nucleus”
- small, relatively simple cells
–Single-celled organisms
–May not require oxygen
–No organelles (with membranes)
2 kinds of cells: prokaryotic and eukaryotic
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• A prokaryotic cell has:
- plasma membrane
- rigid cell wall
– sticky capsule Ribosomes
Figure 4.4
Capsule
Cell wall
Plasmamembrane
Prokaryoticflagella
Nucleoid region(DNA)
Pili
– Nucleoid region with DNA
– Some w/ flagella
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• Prokaryotic cells, Bacillus polymyxa
Figure 4.4x1
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- true nucleus
- larger: 10-100 microns
- often multicellular
- organelles surrounded by membranes
- usually need O2
Eukaryotic cells - functional compartments
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• a group of organelles that manufactures and distributes cell products
• nucleus
• endoplasmic reticulum (ER), ribosomes
• Golgi complex, vesicles
Endomembrane System
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• largest organelle
• nuclear envelope
• contains DNA that directs cell’s activities
• DNA copy goes into every progeny cell
nucleus is the control center
ENDOMEMBRANE SYSTEM
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Figure 4.6
Chromatin
Nucleolus
Pore
NUCLEUS
Two membranesof nuclearenvelope
ROUGHENDOPLASMICRETICULUM
Ribosomes
nuclear pores
nucleus
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• Makes proteins, membranes
Rough endoplasmic reticulum
1 2
3
4Transport vesiclebuds off
Ribosome
Sugarchain
Glycoprotein
Secretory(glyco-) proteininside transportvesicle
ROUGH ER
Polypeptide Figure 4.8
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SMOOTH ER
ROUGHER
Nuclearenvelope
Ribosomes
SMOOTH ER ROUGH ER
Figure 4.9
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• The Golgi complex finishes, sorts, and ships cell products
Golgiapparatus
“Receiving” side ofGolgi apparatus
Transportvesiclefrom ER
Newvesicleforming
Transport vesiclefrom the Golgi
Golgi apparatus
“Shipping”side of Golgiapparatus Figure 4.10
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• sacs of digestive enzymes budded off the Golgi
• Fuse with membrane around debris
Lysosomes
LYSOSOME
Nucleus
Figure 4.11A
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• Lysosomal enzymes
– digest food
– destroy bacteria
– recycle damaged organelles
– function in embryonic development in animals
– Storage of undigestable waste Pombe’s disease - glycogen
Tay-Sachs disease - lipids
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Figure 4.11B
Rough ER
Transport vesicle(containing inactivehydrolytic enzymes)
Golgiapparatus
Plasmamembrane
LYSOSOMES
“Food”
Engulfmentof particle
Foodvacuole
Digestion
Lysosomeengulfingdamagedorganelle
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• synthesizes lipids
• regulates carbohydrate metabolism (liver)
• breaks down toxins and drugs (liver)
• Stores Ca++ in muscle cells
Smooth endoplasmic reticulum
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• Nucleus, ribosomes, RER ,SER, Golgi, vesicles
Endomembrane system
Transport vesiclefrom ER
Rough ER
Transport vesiclefrom Golgi
Plasmamembrane
Vacuole
LysosomeGolgiapparatusNuclear
envelope
Smooth ER
Nucleus
Figure 4.14
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• Vacuole in plants
– Lysosomal
– storage of pigments, poisons
– Water relations
Centralvacuole
Nucleus
Figure 4.13A
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• plant cells
– large central vacuole
– rigid cell wall
– chloroplasts
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• in plants and some protists
• convert solar energy to chemical energy in sugars
Chloroplasts
Chloroplast Stroma
Inner and outer membranes
Granum
IntermembranespaceFigure 4.15
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Figure 4.16
Outermembrane
Mitochondrion
Intermembranespace
Innermembrane
Cristae
Matrix
• cellular respiration
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• network of protein fibers
The CYTOSKELETON helps organize a cell’s structure and activities
Figure 4.17A
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microfilamentIntermediate
filament
microtubule
Actin subunit Fibrous subunitsTubulinsubunit
7 nm 10 nm25 nm
Cell shape, movement
reinforce cell, anchor organelles
cell rigidity, anchor & tracks for organelles, mitosis
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• Nuclei (yellow) and actin (red)
Figure 4.6x
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• locomotor appendages
• composed of a core of microtubules wrapped in the plasma membrane
Cilia and flagella
Basal body
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Surfaces allow exchange of signals and molecules.
• Plant cells connect by plasmodesmata
Cell surfaces protect, support, and join cells
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Figure 4.19A
Vacuole
Layers of one plant cell wall
Walls of two adjacent plant cells
PLASMODESMATA
Cytoplasm
Plasma membrane
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• Animal cells - surrounded by an extracellular matrix
–sticky layer of glycoproteins
–binds cells together in tissues
–can also protect and support cells
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• Tight junctions can bind cells together into leakproof sheets
• Anchoring junctions link animal cells
• Gap junctions allow substances to flow from cell to cell
TIGHTJUNCTION
ANCHORING JUNCTION
COMMUNICATINGJUNCTION
Plasma membranes ofadjacent cells
ExtracellularmatrixFigure 4.19B
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Eukaryotic organelles fall into 4 functional groups
• 1. Manufacture and transport – dependent on network of membranes
- Nucleus
- Ribosomes
- Rough, smooth ER
- Golgi apparatus
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2. Breakdown – all single-membrane sacs
• Lysosomes (in animals, some protists)
• Peroxisomes
• Vacuoles (plants)
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3. Energy Processing – involves extensive membranes embedded with enzymes
• Chloroplasts
• Mitochondria
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4. Support, Movement, Communication
• Cytoskeleton – includes cilia, flagella, filaments, microtubules
• Cell walls
• Extracellular matrix
• Cell junctions
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