Cell Organelles
and
Cell Processes
Some Important Terms
 Prokaryotic
cell: cell that does not contain
a nucleus or any other membrane bound
organelles
 Eukaryotic cell: cell that does contain a
nucleus and membrane bound organelles


Plant cells
Animal cells
Fluid Mosaic Model
Cell Membrane

Structures:

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Functions:

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Lipid bilayer
Protein channels
Carbohydrate chains
Regulates what enters and leaves the cell
Protection
Support
Other:

Found in both plants and animals
Nucleus

Structures:

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Functions:

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Nuclear envelope
Nucleolus
Nuclear pores
Chromatin
Control center of the cell (the “brain”)
Contains all DNA/RNA
Other:

Found only in eukaryotic cells
Chloroplast

Structures:
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Functions:
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Thylakoid membrane
Grana
Stroma
Inner and outer membrane
Chlorophyll
Captures energy from sunlight and converts it
into chemical energy Photosynthesis
Other:

Found only in plants!
Lysosome
 Structures:

Filled with enzymes
 Functions:


Digestion of lipids, carbohydrates, and
proteins into smaller molecules
Break down broken organelles
 Other:

AKA… Junk collector, trash collector,
garbage truck
Vacuoles
 Structures:

No main structures
 Functions:

Stores water, salt, proteins, and carbohydrates
 Other:

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Large in plants
Only some animals cells have one and they are small
Mitochondria
 Structures:
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Inner and outer membranes
Matrix
Intermembrane space
 Functions:

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Convert chemical energy stored in food into
compounds that are more convenient for cells to use
called cell respiration
Makes ATP (energy molecule)
 Other:

AKA… “Powerhouse”
Endoplasmic Reticulum (ER)
 Structures:

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Cisternae
Cisternal space
Smooth ER: no ribosomes
Rough ER: covered in ribosomes
 Functions:

Lipid components of membrane are assembled, along
with proteins and other molecules
 Other:

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AKA… “Assembly Line”
Eukaryotes only
Ribosomes
 Structures:

Small particles of RNA
 Functions:

Assembles proteins (machine in the factory)
Golgi Apparatus (GA)

Structures:

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Functions:

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Cisternae
Modifies, sorts, and packages proteins and
other materials from the ER for storage in the cell
or secretion
Other:

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Only found in eukaryotes
“Customization Shop”
“Post Office”
Cell Wall
 Structures:

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Carbohydrates
Proteins
Cellulose
 Functions:

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Support plant cells
Protect
 Other:
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Found only in plant cells
Cytoskeleton
 Structures:
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Microfilaments
Microtubules
Intermediate filaments
 Functions:

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Helps cell maintain shape
Allows for movement of organelles throughout cell
Cells
14
and Their
Environment
•The structure of the cell membrane plays
an important role in maintaining
homeostasis within the cell.
•Substances are moved in and out of cells
through cell transport mechanisms
(osmosis, diffusion, pumps and vesicles)
Osmosis
 Structures


Involved:
Semipermeable membrane
Water molecules and a solute
 Function:
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Diffusion of water through a semipermeable
membrane
High [water] to low [water]
Water moves from an area of low [solute] to high
[solute]
Goal is to reach equilibrium
Hypertonic vs HypOtonic

Hypertonic: solution has a higher [ ] than cell

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Hyp

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hyper = higher
Water will move out of the cell cell shrivels
up and becomes dehydrated
Otonic: solution has a lower [ ] than cell
Hypo = low
Water will move into the cell cell expands
Isotonic: the [ ] is the same inside and outside
the cell

Equal movement into and out of cell
Osmosis
Diffusion
 Structures

Involved:
Molecules
 Function:

Molecules move from an area of high [ ] to
an area of low [ ] in order to reach
equilibrium
Facilitated Diffusion

Structures Involved:

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Function:

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Protein channel
Cell membrane
Molecules
Protein channels allow large molecules to pass
through the membrane
Moves molecules from high [ ] to low [ ]
Other:

Every protein channel is specific
Protein Pumps
 Structures

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
Involved:
Protein pump
Cell Membrane
Ions
 Function:

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Movement of molecules against the [ ]
gradient
Molecules move from low [ ] to high [ ]
Requires ATP (energy)
Endocytosis & Exocytosis
 Structures



Involved:
Membrane
Food and water molecules (endocytosis)
Waste (exocytosis)
 Function:

Endo: taking materials into the cell by infolds of the
membrane
 Phagocytosis:
bringing food into cell
 Pinocytosis: bringing water into the cell

Exo: materials exiting the cell
 Other:

Requires energy
Endocytosis & Exocytosis