Chapter 7 A view of the cell

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Chapter 7 A view of the cell
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The History of the Cell Theory (p 172)

• Compound Light microscopes
• Invented by Anton van Leeuwenhoek
• 1500 x
• Electron microscopes
• Scanning electron microscope (SEM,????)
• Surface of 3D objects
• Transmission electron microscope (TEM, ????)
• Inside a cell
• Scanning Tunneling microscope (STM)
• Viewing atoms

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The History of the Cell Theory (p172)
Robert Hooke- first to use the word cells The
cell theory (P 172) 1. All organisms are composed
of one or more cells. 2. The cell is the basic
unit of structure and organization of
organisms. 3. All cells come from preexisting
cells.
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Two Basic Cell Types (p173)
Prokaryotes (????) Cells that do not contain
any membrane- bound organelles Most unicellular
(one cell) organisms bacteria
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Two Basic Cell Types (p173)
Eukaryotes (????) Cells that do contain
membrane- bound organelles Most multicellular
(many cells) organisms plants, animals,
etc. Some unicellular organism too algae
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Prokaryote Vs. Eukaryote
Prokaryote Eukaryote
No membrane-bound organelles Membrane-bound organelles
No nucleus Nucleus
Small (0.001-0.01 mm) Large (0.01-0.1mm)
Small Ribosomes Large Ribosomes
Small, normally circular DNA Large, chromosome DNA
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Maintaining a Homeostasis (p175)
Homeostasis- stable state of a healthy
functioning cell Plasma Membrane- guard of the
cell first step towards homeostasis Selectiv
e permeability (?????)- a process in which a
membrane allows some molecules to pass through
while keeping others out. Transport proteins-
special tunnels or doors that only let in
specific molecules
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Structure of the Plasma Membrane (p177)
Phospholipids- hydrophilic heads and hydrophobic
tails make a double layered wall
Cholesterol- help keep membrane fluid and
stable Carbohydrates- used in cell
communication
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Structure of the Plasma Membrane
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Fluid Mosaic Model
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Cell Organelles

• Organelles- tiny organs inside the cell
• have a specific job to maintain homeostasis
• Some are in all cells membrane
• Some are only found in either animal or plant
  cells

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Cellular Boundaries (p179)
Animal Cell Plasma membrane
Plant Cell Plasma membrane and Cell wall
(cellulose)
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The Nucleus (???) (p180)
The brain of the cell contains DNA (Chromatin)
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Making proteins!
Ribosomes- take copy of DNAs information (mRNA)
and use it as a guide to create
proteins Endoplasmic Reticulum- site of
chemical reactions inside cell Smooth ER- no
ribosomes Rough ER- ribosomes
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Transportation Center
Golgi Apparatus- puts proteins into small
membrane-bound packages called vesicles which
are sent out and around the cell Vacuole
s- storage compartments for food, enzymes,
etc. In plant cells- they are very large and
hold lots of water In animal cells- very small
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Vacuoles
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Cellular Digestion
Lysosomes- sacs of digestive enzymes that break
down old organelles, food, and viruses/bacteria
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Making Energy in Plant Cells (p184)
Chloroplasts- perform photosynthesis to make
energy from sunlight in planets and some
unicellular organisms Chlorophyll- chemical that
absorbs all wavelengths of sunlight, expect
green
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Making Energy in Animal Cells (p185)
Mitochondria- power house of the cell produces
ATP(energy unit for cells) by breaking
down sugars and other organic compounds
(cellular respiration)
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Organelles for Support (p 185)
Cytoplasm- clear gel-like fluid inside cells
help holds organelles in place Cytoskeleto
n- Bones of the cell crossing rods, filaments,
and tubes, that hold the cells shape. Also act
at a railroad system to move things around
the cell
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The Cytoskeleton
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Organelles for Support (p187)
Centrosome- move chromosomes during cell division
in animal cells
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Locomotion (p187)
Flagella- long, wipe-like tail that pushes and
rolls the cell Cilia- short, hair-like
paddles that push the cell along
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Animal Cells Vs. Plant Cells
Organelle Plants only Animals only Both
Plasma Membrane X
Cell Wall X
Nucleus X
Ribosomes X
Endoplasmic Reticulum X
Gogi Apparatus X
Lysosome X
Vacuole (large) (small) X
Centrioles X
Mitochondria X
Chloroplasts X
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Tour of an Animal Cell
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Tour of an Plant Cell
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• P 192

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Homework

• Ch. 7 workbook pages (Due Friday)
• Cell labeling practice sheet