Transcript Vacuoles and Peroxisomes

Vacuoles and
Peroxisomes
By Sam, Katie N, Katie V and Jess
Vacuoles
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Definition: A vacuole is a large compartment filled with fluid that is in the cytoplasm of
plants cells and animal cells.
A Vacuole is a storage place for sugars, minerals, proteins, and water.
Vacuoles also store and help carry out waste from the cell.
The vacuoles also increase the size of the surface area of the cell: This allows the absorption
of minerals that are necessary for plant and animal nutrition.
Vacuoles are filled up with a liquid called “Cell Sap”
Cell sap contains the components of water, salt and sugar
Vacuoles are not a part of the endomembrane system because they do not communicate with
other organelles.
General Information: They enable the cell to change shape.
They help the cell maintain its internal pH
They help isolate materials that might be harmful or a threat to the cell.
They help the cell maintain internal hydrostatic pressure.
Animal Cell Vacuoles
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Vacuoles in animals cells tend to be
much smaller then those in plant cells.
Vacuoles in animal cells take part in the
process of endocytosis and exocytosis.
Exocytosis is the process in which
directs vesicles to the cell membrane and
endocytosis is the process in which cells
absorb materials.
In an animal cells, the vacuole fills with
solid food particles being digested and
waste material that is on its way out of
the cell.
Vacuoles are also a part of the process
phagocytosis and pinocytsosis.
http://images.google.ca/imgres?imgurl=http://
Plant cell Vacuoles
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The membrane bound sac helps with
cellular waste products.
Vacuoles in plant cells tend to be much
larger then in animal cells.
They play a very important role in turgor
pressure, as water collects in cell vacuoles
producing rigidity in the plant.
Without sufficient water pressure in the
vacuole is reduced and the plant wilts.
In plant cells there are either one or more
large vacuoles.
The vacuole (s) occupies more then 30% of
the cells volume and can be up to 90%
depending on the plant type and conditions.
Toxins in the vacuole can also help keep
away predators.
http://wikitextbook.co.uk/images/0/08/Plant_cell_structure.png
Here is the electron micrograph of the plant
Here is a paramecium, its vacuoles are
distributed throughout the cell.
Where Can We Find Them!?
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Vacuoles are mostly found in plant cells, however they can also be found in animal cells. They
are also found in protists which are eukaryotic cells that consist of simple organisms
unicellular or multi-cellular without complex tissues and vacuoles can also be found in
budding yeast cells which are a eukaryotic unicellular organism that are produced asexually
by budding (no fertilization).
The vacuoles are located in the cytoplasm of the cell.
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http://www.tvdsb.on.ca/westmin/science/sbi3a1/cells/vacuole.htm
Peroxisomes
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The are organelles found in eukaryotic
cells – plant and animal
They collect toxic peroxides which are by
products of cellular chemical reactions
Peroxides are broken down inside the
peroxisome by enzyme catalysts
enzymes that produce the toxic hydrogen
peroxide are transported into the
peroxisomes by the cytoplasm after they
are synthesized by free ribosomes
Vacoules and Peroxisomes are related
because neither of them communicates
with other organelles inside the cell
http://erocha.freehosting.net/TroutImages/Marine_Snail_Peroxisome_WEB.jpg
What they look like
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They are round or oval vesicles surrounded
by a phosolipid bilayer
Inside the vesicle are many, many enzymes
Each peroxisome is a single membrane
Each cell contains several hundred
peroxisomes
They resemble a lysosome but are not the
same
They are self replicating
Size is variable, but it is roughly 700nm
A peroxisome is found in the cytoplasm of a
cell
The organ that peroxisomes are most
abundant in is the liver
http://content.answers.com/main/content/wp/en/thumb/8/88/300px-Peroxisome.jpg
Inside the Cell
http://www.x-ald.nl/cell.jpg
Peroxisomal Diseases
• Three types of disorders related to peroxisomes: peroxisome biogenesis disorders,
peroxisomal multi-enzyme disorders, and peroxisomal single-enzyme disorders.
• Peroxisomes biogenesis disorders: the peroxisomes do not work at all, or aren’t forming
• Peroxisomal multi-enzyme disorders: certain proteins inside the peroxisome do not
develop, but the peroxisome still tries to do its job
• Peroxisomal single-enzyme disorders: occur when the peroxisome is working properly
with the exception of a defect in a single enzymatic process (this sounds like the disease
would be less sever but that isn’t the case)
• Zellwegger Syndrome is an example of a peroxisome biogenesis disorder. A child who is
born with ZS would be very deformed and most likely suffers from seizures. It is a fatal
disease, the average lifespan is about 1 year
• Rhizomelic chondrodysplasia punctata or RCDP is a multi-enzyme disorder that results in
skeletal abnormalities, and causes many problems with the psychomotor development
Bibliography
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http://en.wikipedia.org/wiki/Vacuole
http://www.biology4kids.com/files/cell_vacuole.html
http://www.pacifier.com/~mstephe/peroxisome.htm
http://www.rkm.com.au/CELL/organelles/peroxisome.html
• The grade 11 Bio Text Book