bio 1100 chapter 4 sp11
TRANSCRIPT
Chapter 4 Chapter 4 Life’s Home: The CellLife’s Home: The Cell
Discovery of CellsDiscovery of Cells• Robert Hooke
– cork – the term “cell”
• Anton van Leeuwenhoek– microscope
Cells are the Fundamental Units of LifeCells are the Fundamental Units of Life
• The cell theory– All organisms are composed
of one or more cells– The cell is the basic living unit
of life (organization) – All cells arise from preexisting
cells
Anatomy of the Generalized CellAnatomy of the Generalized Cell
The cell is the smallest unit that shows the properties of life
ALL cells share 3 general structures
DNA
Cytoplasm (pg. 68)
Plasma membrane
The Two Major Categories of CellsThe Two Major Categories of Cells
– Two major kinds of cells (pg. 65):
• PROKARYOTICPROKARYOTIC cells
–“before nucleus”
• EUKARYOTICEUKARYOTIC cells
–eu = “true”
–karyon = “nucleus”
Prokaryotic CellsProkaryotic Cells• Lack a membrane-bound nucleus
– DNA in nucleoid region
• Structurally smaller and simpler than eukaryotic cells (most are unicellular)
• Prokaryotic cells are placed in two taxonomic domains:
– Bacteria
– Archaea
• Live in extreme habitats
Prokaryotic Cells - BacteriaProkaryotic Cells - Bacteria
Eukaryotic Cells (Eukaryotic Cells (eueu = “true”) = “true”)
• Eukaryotic cells are members of the domain Eukarya
• Much larger than prokaryotic cells
• Cells contain a membrane bound nucleus
– DNA (genetic material)• Eukaryotic cells are compartmentalized
– They contain membrane bound structures called organelles
Figure 4.2Figure 4.2
Comparison of
prokaryotes and
eukaryotes
pg. 64
Two Main Types of Eukaryotic CellsTwo Main Types of Eukaryotic Cells
• Animal cells and Plant cells
The NucleusThe Nucleus
– The NUCLEUS is the control center of the cell (pg. 69).• Contains DNA (genetic
information)–chromatin
• Nuclear envelope• Nucleolus (pg. 72)
–rRNA
nucleus
nuclearpores
(b) Yeast cell
nuclearenvelope
nuclearpores
nucleolus
chromatin
(a) Structure of the nucleus
The nucleus contains chromatin which condenses and coils into chromosomes just before the cell divides
The Endomembrane SystemThe Endomembrane System
– An extensive system of interior membranes that divides the cell into compartments – pg. 73• Nuclear envelope• Endoplasmic reticulum (ER)• Golgi apparatus (complex)• Vesicles
Ribosomes & The Endoplasmic ReticulumRibosomes & The Endoplasmic Reticulum
– Two forms of ER:–Rough endoplasmic
reticulum (pg. 72)»ribosomes are the
sites of protein synthesis – pg. 71
–Smooth endoplasmic reticulum
»Lipids & detoxification»pg. 74
Endoplasmic Reticulum (ER) – pg. 70 & 71Endoplasmic Reticulum (ER) – pg. 70 & 71
nuclear enveloperibosomes
0.08 m
roughendoplasmic
reticulum
smoothendoplasmic
reticulum
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The Golgi Apparatus (Complex) The Golgi Apparatus (Complex)
• A specialized set of membranes derived from the endoplasmic reticulum (ER) that modifies, sorts, and packages important molecules into vesicles.
»receives vesicles from ER (acts as a transfer station) – pg. 73
Fig 4.8 pg. 73Fig 4.8 pg. 73
Lysosomes & Cellular RecyclingLysosomes & Cellular Recycling
– Contain digestive enzymes that digest warn-out organelles and foreign materials that enter the cell – pg. 74• Produced by the Golgi
apparatus• Waste disposal and
recycling
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Endomembrane System SummaryEndomembrane System Summary
Energy-Related OrganellesEnergy-Related Organelles
• Chloroplasts (pg. 84)
– Photosynthesis in plants (leaves)
• Capture energy from sunlight
• Mitochondria (pg. 76)
– Involved in cellular respiration
• Extract energy (ATP) from food molecules
– “powerhouse” of the cell
Mitochondria – pg. 76Mitochondria – pg. 76
The Cytoskeleton – pg. 76The Cytoskeleton – pg. 76
• Maintains cell shape and assists in movement of the cell and organelles
• Three types of macromolecular fibers
– Microfilaments
– Intermediate Filaments
– Microtubules
Cilia and Flagella – pg. 79Cilia and Flagella – pg. 79
– Slender, movable extensions of the plasma membrane.
– Used for movement
Compare and Contrast plant and animal cells.
Animal Cells Plant Cells
•Plasma membrane•Cytoplasm•Nucleus
•Cell wall•Plasma membrane•Cytoplasm•Central vacuole•Chloroplasts•Nucleus
The Eukaryotic CellThe Eukaryotic Cell
Figure 4.4
nuclear envelope
nuclear poresDNA
nucleolus
nucleussmooth endoplasmic
reticulum
free ribosomes
cytosol
mitochondria
lysosomes
Golgi complex
plasma membrane
transport vesicle
rough endoplasmic
reticulum
cytoskeleton
The Plant CellFigure 4.16
nuclear envelopenuclear pores
nucleolus
nucleus
plasma membrane
cytoskeleton
smooth endoplasmic reticulum
rough endoplasmic reticulum
free ribosomes
cytosol
chloroplast
mitochondrion
cell wall
centralvacuole
DNA
Golgi complex
Plant cells have a cell wall, chloroplasts, and a central vacuole, while animal cells do not.
Structures in Plant and Animal CellsStructures in Plant and Animal Cells
Table 4.1
Chapter 4 ReviewChapter 4 Review
• Review the 3 parts of the cell theory (pg. 63-64)• Compare & contrast a prokaryotic versus a
eukaryotic cell (pg. 64-65, Fig 4.2)• List the 3 components found in ALL cells• List the principle components of the eukaryotic cell
– what is the function of each component?– pg. 65-80 Table 4.1
• Compare and contrast a plant versus an animal cell (pg. 80-84)