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A Tour of the Cell, Part II
CHAPTER 4
Features of the Eukaryotic Cell, cont.
 Endomembrane
System, continued
o Golgi Apparatus
o Lysosomes
o Vacuoles
 Energy
Converting Organelles
o Chloroplasts
o Mitochondria
 Cytoskeleton
o
Cell Shape
o Cell Movement
Proteins and Lipids Leave the ER Enroute to the Golgi
Proteins Are Transported in Vesicles to the Golgi
Figure 4.11
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 II
CHAPTER 4
Features of the Eukaryotic Cell, cont.
 Endomembrane
System, continued
o Golgi Apparatus
o Lysosomes
o Vacuoles
 Energy
Converting Organelles
o 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 II
CHAPTER 4
Features of the Eukaryotic Cell, cont.
 Endomembrane
System, continued
o 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
Flow of Proteins Through the Endomembrane System
Figure 4.15
A Tour of the Cell, Part II
CHAPTER 4
Features of the Eukaryotic Cell, cont.
 Endomembrane
System, continued
o 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
Unusual Features of Mitochondria and Chloroplasts
• 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.
A Tour of the Cell, Part II
CHAPTER 4
Features of the Eukaryotic Cell, cont.
 Endomembrane
System, continued
o 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.
Cilia and Flagella
Paramecium Cilia
Cilia found on anchored cells create currents and streaming in liquids
Figure 4.19c
A Tour of the Cell
CHAPTER 4
Microscopes as Windows on Cells
o Types of Microscopes
o Magnification and Resolution
 Categories of Cells
 Features of Prokaryotic Cells
 Features of Eukaryotic Cells
o Membrane Structure
o Nucleus and Ribosomes
o Endoplasmic Reticulum (ER)
o Golgi Apparatus
o Lysosomes
o Vacuoles
o Energy
Converting Organelles
– Chloroplasts
– Mitochondria
o Cytoskeleton
– Cell Shape
– Cell Movement