Download Organelles

•Between the cell membrane and the nucleus lies the
cytoplasm (SIET – oh –PLAZ – uhm), which contains the
various organelles of the cell
•The organelles are surrounded in a jelly like watery fluid
called the cytosol (SIET – oh –SAWL )
• Dissolved in the cytosol are the salts, minerals, and organic
molecules
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Comes from the Greek mitos, meaning
“thread”, and chondrion, meaning “grain”
Are the power houses of the cell and contain
the molecular machinery for the conversion
of energy from the breakdown of glucose into
adenosine triphosphate (ATP), the energy
used by all cells.
(MIET – oh –KAHN –dree –uh)
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The energy stored in the high energy
phosphate bonds of ATP is then available to
power cellular functions.
Mitochondria are mostly protein, but some
lipid, DNA and RNA are present.
The unique structure of these organelles can
be seen under the electron microscope.
•The metabolic activity of
the cell is related to the
number of cristae (KRIStee) and the number of
mitochondria within a cell.
•Cells with large amounts
of metabolic activity, such
as heart muscle/sperm
cells, have many well
developed mitochondria.
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These generally spherical organelles have an
outer membrane surrounding an inner
membrane that folds (cristae) to provide
more space for chemical reactions
These reactions are oxidative
phosphorylation and electron transport
enzymes.
Those big words are just ways that ATP is
formed
•Mitochondria
have their own
DNA, and new
Mitochondria are
created only when
existing ones grow
and divide.
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Ribosomes are small organelles composed of
ribosomal RNA (rRNA) and 80 some different
proteins.
Inside the cell’s nucleus rRNA and proteins
are cobimed to form Ribosomes
The Ribosomes are then transported to
cytosol
Ribosomes play an important part in the
production of proteins.
•Ribosome's are the
most common
organelle in many
cells
• Ribosome’s do not
have an outer
membrane
 A system of membrane tubes and sacs
 The ER functions acts like a highway
for the cell, providing a road for
molecules to move form one cell to
the other.
 The number of ER in a cell depends on
the activity of the cell and can change
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Rough Endoplasmic Reticulum
- (Rough ER)
- has attached ribosome's that give it a rough
appearance
Is usually in cells that make a large to be
exported from or imported to the cell
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Smooth ER
-is not covered with ribosomes, giving it a
smooth appearance
- Smooth ER is involved with the production
of steroids in gland cells, the control of
calcium levels in muscle cells, and the
breakdown of toxic substances by liver cells.
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The Golgi Complex is responsible for the
packaging of proteins in the cell.
The Golgi is a curved membrane stack
resembling a stack of pancakes.
The Golgi bodies package proteins produced
in the ribosome and transport them via the
ER.
Proteins within the rough ER bud off and are
transported to the Golgi where they are
further modified and packaged for export.
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All this packaging is necessary so the cell is
able to recognize the protein as 'self'.
If the protein is not recognized the immune
system will treat the protein as a foreign body
known as an antigen.
When this happens the immune system
undergoes an immune response.
Viruses and bacteria that cause disease are
recognized as antigens(foreign proteins) and
attacked immediately.
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Are small, spherical organelles that enclose
more than 40 hydrolytic enzymes
These enzymes can digest proteins,
carbohydrates, lipids, DNA and RNA.
They may also digest old organelles and
viruses and bacteria that has invaded a cell.
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Lysosomes are common in the cells of
animals, fungi, and protists, but they are rare
in plant cells.
For example, the human hand begins as a
solid structure in the embryo.
As the embryo develops, lysosomes enzymes
selectively destroys tissue to form the spaces
the spaces between the fingers.
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Just as your body needs a skeleton to keeps
its size and shape, a cell need a structure to
maintain its shape and size.
This is called a Cytoskeleton, a network of
long protein strands located in the cytosol.
In addition to providing support, the
cytoskeleton helps with the movement of
organelles with in the cytosol.
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Two major components of the cytolskeleton
are microfilaments and microtubules.
Microfilaments are threads made of a
protein called actin.
Each microfilament is made of many actins
molecules that are linked together to form a
polymer chain.
The microfilaments help with cell movement
and play a role in the contraction of muscles.
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Hollow tubes that extend outward from a
central point near the nucleus to various cites
near the cell membrane.
These tubules will bundle together to form
spindle fibres
Spindle fibres help with the movement of
chromosomes during cell division
When cell division is complete the unbundle,
and continue to provide support for cell.
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Cillia ( SIL-ee-uh0
Flagella (fluh-JEL-uh)
Are hair like organelles that extend from the
surface of the cell, where they assist in
movement.
If these organelles are short and in large
numbers on the cell they are called cillia
If they are long and less numerous on a cell
they are called flagella
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The external surfaces of many single celled
organisms are covered with cillia.
The movements of these cillia help these tiny
organism move through the water to search
for food and escape predators.
Also found in multicellular organisms,
The cells of your respiratory tract are covered
with cillia, these help to move particles and
debris you inhale back to your throat.
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On many cells, including sperm cells they
have only one flagella that they can whip
back and forth to move.
Cillia and Flagella have a similar structure .
Both organelles are composed of nine pairs of
microtubules arranged around a central pair
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1. Write the main purpose of each organelles
looked at today.
2. What structural feature do cilia and flagella
have in common.