Transcript VACUOLES - Lincoln-Sudbury Regional High School

VACUOLES
By: Jessica Hardwick, Anne Schwartz, and
Bridget Menkis
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Table of Contents
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3. Structure
4. General Function
5. Plant Cells
6. Fungi Cells
7. Animal Cells
8. Contractile Vacuoles
9. Conclusion
10. Sources
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Structure
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Vacuoles are organelles found in cells. They store various substances
essential to the life of the cell. They also store waste to later remove
from the cell.
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General Function
Vacuoles, like vacuums, remove waste products
harmful to the cell. In addition, they store water
and essential nutrients for later use. For this
reason, they are called “storage bubbles”(source
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Source 6
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Plant Cells
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Vacuoles make up about 80% of the volume of a full grown plant cell (source 4)
They are more important in plant cells than any other types of cells
They are surrounded by a membrane called a tonoplast
They store water and food for the plants to use for other processes
They store waste products of the cell
They are called central vacuoles because their function is vital to the plant’s survival and
because they are so large
The greater amount of water the vacuole holds, the more turgor pressure there is. Turgor
pressure increases when there is more sugar and other solutes in the vacuole. This is because
the increase of the solutes causes a need for more water, in which they can be dissolved.
Turgor pressure is applied to the cell wall and therefore makes the plant rigid, keeping its
structure.
– When central vacuoles lack water, the plant droops
Flower petals’ central vacuoles can contain substances
that attract pollinating insects or repel harmful animals or organisms
Osmoregulation- maintains osmotic pressure
Vacuoles push cytoplasm toward the cell membrane, exposing
chloroplasts to light
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Fungi Cells
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Fungal cell vacuoles perform many functions, similar to plant cell vacuoles
They help remove waste product from the rest of the cell
They help maintain the cell’s pH levels so that it can function optimally
Can have multiple vacuoles
Osmoregulation- maintains osmotic pressure
Stores amino acids
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Animal Cells
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Misconception: Some people, to make things simple, say that animal cells do have vacuoles
but animal cells do not have vacuoles. Instead, they contain vacuole-like organelles called
vesicles
– Vesicles: similar function as vacuoles but much smaller than a plant’s central vacuole
– Vesicles perform 2 important functions:
• Exocytosis: disposal of solids and liquids such as proteins, lipids and bacteria out of
cells
• Endocytosis: taking solids and liquids such as proteins, lipids and bacteria into cells
– One cell can have multiple vesicles
Click here for a short animation about endocytosis and exocytosis
Animal Cell Vesicle
Vesicle
Source 1
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Contractile Vacuoles
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Found in protists
Appear to have spokes and a hub (Textbook pg. 62)
– Spokes collect excess water
– Hubs dispose of water (releases it to the outside of the cell)
Necessary in fresh water protists so that they do not burst
Osmoregulation- maintains osmotic equilibrium
Expand and contract as they take in and release liquid
In amoebas: vacuoles move as the amoeba moves
In Ciliates: vacuoles have a definite path in the cell
In Euglena and other flagellates: vacuoles remain
stationary
Click here to watch a short video of an amoeba- pay
attention to the vaculoes moving in it
(youtube video-> can’t watch on school computer)
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Conclusion
• Vacuoles are most important in plant cells
• Vacuoles have a similar function in fungal cells
as plant cells
• Contractile vacuoles are found in protists and
are most important in fresh water organisms
• Vacuoles are important for storage in cells
• Vacuoles collect harmful waste and dispose of
it
• Animal cells have vesicles, not vacuoles
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Sources
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http://imcurious.wikispaces.com/Midterm+Exam+2010+Review+P1
http://micro.magnet.fsu.edu/cells/plants/vacuole.html
http://www.vacuumreviewer.com/hoover-vacuum-cleaners/
http://www.buzzle.com/articles/vacuole-function.html
http://www.biology4kids.com/files/cell_vacuole.html
http://www.chem1.com/acad/sci/aboutwater.html
http://www.biology-online.org/dictionary/Turgor_pressure
http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/eustruct/lyso.html
http://www.cellsalive.com/cells/cell_model.htm
http://www.iscid.org/encyclopedia/Contractile_Vacuole
http://www.britannica.com/EBchecked/topic/135337/contractile-vacuole
http://www.linkpublishing.com/video-transport.htm
http://ploegerchiropractic.com/blog/page/2/
http://www.itteringham.com/nature.html
http://botany.thismia.com/2010/02/
Biology: concepts & Connections By: Campbell, Mitchell, Reece
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