a tour of the cell, part ii chapter 4 features of the eukaryotic cell, cont. endomembrane system,...
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Figure 4.11 Proteins Are Transported in Vesicles to the GolgiTRANSCRIPT
A Tour of the Cell, Part IICHAPTER 4Features of the Eukaryotic Cell, cont. Endomembrane System, continuedo Golgi Apparatus
o Lysosomes
o Vacuoles
Energy Converting Organelleso Chloroplasts
o Mitochondria
Cytoskeleton o Cell Shape
o Cell Movement
Proteins and Lipids Leave the ER Enroute to the Golgi
Figure 4.11
Proteins Are Transported in Vesicles to the Golgi
The Golgi Apparatus• The Golgi apparatus
– Refines, stores, and distributes the chemical products of cells.
– Acts like a finishing and shipping station (UPS or FedEx) in the cell
A Tour of the Cell, Part IICHAPTER 4Features of the Eukaryotic Cell, cont. Endomembrane System, continuedo Golgi Apparatus
o Lysosomeso Vacuoles
Energy Converting Organelleso Chloroplasts
o Mitochondria
Cytoskeleton o Cell Shape
o Cell Movement
Lysosomes• A lysosome is a membrane-enclosed sac containing
digestive enzymes
– The enzymes break down macromolecules and ingested debris within vacuoles
– Serves as the “Greeting and Garbage Service” of the cell
Lysosome Formation
Figure 4.13a
A Tour of the Cell, Part IICHAPTER 4Features of the Eukaryotic Cell, cont. Endomembrane System, continuedo Golgi Apparatus
o Lysosomes
o Vacuoles
Energy Converting Organelles o Chloroplasts
o Mitochondria
Cytoskeleton o Cell Shape
o Cell Movement
Vacuoles• Vacuoles are membranous sacs.
– Two types are the contractile vacuoles of protists and the central vacuoles of plants.
– Used to store food, water, or wastes
Paramecium vacuole
Figure 4.15
Flow of Proteins Through the Endomembrane System
A Tour of the Cell, Part IICHAPTER 4Features of the Eukaryotic Cell, cont. Endomembrane System, continuedo Golgi Apparatus
o Lysosomes
o Vacuoles
Energy Converting Organelles o Chloroplasts
o Mitochondria
Cytoskeleton o Cell Shape
o Cell Movement
Energy Conversion Organelles: Chloroplasts and Mitochondria
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
Chloroplasts• Chloroplasts are the sites of photosynthesis, the conversion
of light energy to chemical food energy
– They are food production factories and are found only in plants and some protists (algae & seaweed)
Photosynthesis:
Carbon dioxide + water + sunlight
Food energy + oxygen gas
Mitochondria
• Mitochondria are energy conversion factories
• Food energy is converted into usable cellular energy (ATP) through cellular respiration
Cell Respiration:
Food energy + oxygen gas
Carbon dioxide + water + ATP
• Mitochondria and chloroplasts share another feature unique among eukaryotic organelles.
– They contain their own DNA.in the form of small, circular loops.
• The existence of separate “mini-genomes” is believed to be evidence that
– Mitochondria and chloroplasts evolved from free-living prokaryotes in the distant past.
Unusual Features of Mitochondria and Chloroplasts
A Tour of the Cell, Part IICHAPTER 4Features of the Eukaryotic Cell, cont. Endomembrane System, continuedo Golgi Apparatus
o Lysosomes
o Vacuoles
Energy Converting Organelles o Chloroplasts
o Mitochondria
Cytoskeleton o Cell Shape
o Cell Movement
The Cytoskeleton: Cell Shape and Movement
• The cytoskeleton is an infrastructure of the cell consisting of a network of fibers.
– Made of microtubules and microfilaments
• Functions:
– Provide mechanical support, maintain or change its shape
– Provide for whole cell movement
Cytoskeleton: Cilia and Flagella• Cilia and flagella are hair-like appendages, that provide a
means of cellular movement.
– Flagella propel the cell in a whiplike motion.
– Cilia move in a coordinated back-and-forth motion.
Paramecium CiliaCilia and Flagella
Figure 4.19c
Cilia found on anchored cells create currents and streaming in liquids
A Tour of the CellCHAPTER 4Microscopes as Windows on Cellso Types of Microscopes
o Magnification and Resolution
Categories of Cells Features of Prokaryotic Cells Features of Eukaryotic Cellso Membrane Structure
o Nucleus and Ribosomes
o Endoplasmic Reticulum (ER)
o Golgi Apparatus
o Lysosomes
o Vacuoleso Energy Converting Organelles
– Chloroplasts
– Mitochondria
o Cytoskeleton
– Cell Shape
– Cell Movement