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
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 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
Figure 4.15 Flow of Proteins Through the Endomembrane System
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
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 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. Paramecium Cilia Cilia and Flagella
Figure 4.19c Cilia found on anchored cells create currents and streaming in liquids
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