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Cell Theory and Cells
The Cell Theory
1. All living things are made out of cells
2. All cells arise from pre-existing cells
3. Living things function because of the
combined activity of their cells
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Exceptions to the Cell Theory
Some cell structures can reproduce on
their own!!
Ex) Mitochondria and Chloroplasts
•
Viruses are not cells, but they can
reproduce
•
The first cell could not have come from a
pre-existing cell
Virus attacking a host cell
Cell Organelles (Parts)
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1.
2.
3.
4.
5.
6.
7.
Specialized parts that perform specific functions
Organelles common to Animal & Plant Cells:
Cell Membrane (Plasma Membrane)
Nucleus
Nucleolus
Cytoplasm
Endoplasmic Reticulum (ER)
Ribosomes
Mitochondria
8.
9.
Golgi Apparatus
Vacuoles
Nucleus: Control center of cell,
contains chromosomes (DNA)
• Nucleolus: Found inside the nucleus
Cell Membrane: Transports substances into
and out of a cell. (Based on size –
selectively permeable)
Made of lipids and proteins
Cytoplasm: Jelly-like fluid which
surrounds the organelles
Endoplasmic Reticulum (ER
Highway): Network of channels
for transport
Ribosomes: Make Proteins
Mitochondria: Make Energy / ATP
(Mighty Mitochondria)
Golgi Bodies: Stack of tubes that
package substances
Vacuoles: Storage Bins for water and
food. Very Large in PLANTS
Organelles only in Animal Cells:
• Lysosome: Digest food or cell parts
• Centrioles: Help in Cell Division
Organelles only in Plant Cells:
• Chloroplast: Green in color, contain chlorophyll
for photosynthesis (to make food)
• Cell Wall: Made of hard material called
cellulose, supports and protects
Cell Membrane- Fluid Mosaic Model
Diffusion through a membrane:
The natural flow is High to Low
That’s the way diffusion goes!
Which diagram illustrates diffusion?
Hint: High to Low
Which direction will the CO2 diffuse?
Which direction will the O2 diffuse?
Which cells did water diffuse out of?
Which cell organelle is shown here?
Animal cells are specialized based on
DNA