Download 1 Cell Organelles in Plant and Animal Cells

Cell Organelles in Plant and
Animal Cells
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C HAPTER
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Chapter 1. Cell Organelles in Plant and Animal Cells
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Cell Organelles in Plant and
Animal Cells
List the main organelles found in an eukaryotic cell.
Define the role of a ribosome.
Describe the functions of the mitochondria, endoplasmic reticulum, and Golgi apparatus.
Explain the function of a vesicle, a vacuole, and a lysosome.
Do brain cells have the same internal structures as your other cells?
Yes. Although brain cells look quite different from your other cells, they have the same internal structures as other
cells. They need the same structures because they need to perform the same tasks, such as making proteins and
obtaining energy.
Organelles
Eukaryotic cells have many specific functions, so it can be said that a cell is like a factory. A factory has many
machines and people, and each has a specific role. Just like a factory, the cell is made up of many different parts.
Each part has a special role. The different parts of the cell are called organelles, which means "small organs." All
but one of the organelles listed below has a membrane surrounding it. Eukaryotic cells have many of the organelles
listed below - some found only in plant cells, others found only in animal cells, and many in both types of cells.
Prokaryotic cells are "simpler" than eukaryotic cells. Though prokaryotic cells still have many functions, they are
not as specialized as eukaryotic cells. In fact, the only organelle prokaryotic cells have is the one non-membrane
covered organelle, the ribosome.
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Below are the main organelles found in eukaryotic cells ( Figure below):
1. The cell wall both protects and supports the cell. It is made of non-living cellulose. The cell wall is only
found in plant cells.
2. The cell membrane controls what enters and leaves the cell. It also protects the cell. It is made of
phospholipids and is elastic and flexible. It is found in both plant and animal cells.
3. The cytoplasm is the jelly-like substance that surrounds the organelles. It contains the raw materials the cell
uses to make compounds or structures. It is found in both plant and animal cells.
4. The nucleus of a cell controls all the cell activities. It is called the brain of the cell. It contains the DNA
which is the genetic material used to build all of the proteins an organism needs. It is also the largest organelle
of the cell. It is found in both the plant and animal cells.
5. The chromosomes are the coiled strands of DNA inside the nucleus. Each organism has its own number of
chromosomes. There are 46 chromosomes in each human cell. Chromosomes are found in both plant and
animal cells.
6. The centrioles control the movement of the chromosomes during cell division. Centrioles are found in animal
cells only.
7. The ribosome is the only non-membrane covered organelle. They make proteins by joining together amino
acids. They are the smallest and most abundant organelle and is the only organelle found in prokayotic cells.
They are also found in both plant and animal cells.
8. The endoplasmic reticulum (ER) makes lipids, breaks down drugs, and acts as the internal delivery system
for the cell. It is a network of membranes that run throughout the cell. There are two types of ER: rough and
smooth. Rough ER is covered with ribosomes and smooth ER is not. ER is found in both plant and animal
cells.
9. The mitochondria breaks down food to release the energy that the cell can use, ATP (adenosine triphosphate),
through cellular respiration. For this reason they are called the powerhouse of the cell. It has two membranes,
an inner one that is folded over so it can make more energy and an outer one. It also has its own DNA. The
mitchondria is found in both plant and animal cells.
10. The chloroplast changes the sun’s energy into sugar (food), a form of chemical energy, through photosynthesis. It has green pigment called chlorophyll that absorbs sunlight. It also has 2 membranes and its own DNA.
Choloroplasts are only found in plant cells.
11. The Golgi Complex (Golgi Body, Golgi Apparatus) puts the finishing touches on proteins and lipids. It puts
them into vesicles to send to another part of the cell or out of the cell altogether. It is arranged as a stack of
membranes. The golgi is found in both plant and animal cells.
12. The vesicle is a sac of membranes that delivers materials throughout the cell. It is a piece of membrane that
breaks off the golgi complex or the ER. It is found in both the plant and animal cell.
13. The vacuole stores water as well as a variety of materials. Water in the plant supports the leaves. Small
vacuoles are found in the animal cell. Large vacuoles are found in the plant cell.
14. The lysosome digests materials or old worn-out organelles. It contains enzymes. These are only found in
animal cells.
Animal Cells vs Plant Cells
As you’ve no doubt noticed by now by reading the list of organelles and looking at the pictures above, there are
some organelles that are only found in the animal cell and other organelles that are only found in the plant cell as
well as some visual differences. Let’s take a look at these differences.
Animal Cells
Animal cells contain two organelles that plant cells do not have: centrioles and lysosomes. They also have a third
organelle, a vacuole, that is found in plant cells but differs in size and function. The centriole organelles are used to
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Chapter 1. Cell Organelles in Plant and Animal Cells
FIGURE 1.1
This is an animal cell. Notice the lysosome, centrioles, and small vacuoles.
These are only found in animal cells.
FIGURE 1.2
This is a plant cell. Notice the cell wall,
the chloroplasts, and the large vacuole.
These are only found in the plant cell.
move chromosomes around during mitosis and meiosis (cellular reproduction). The lysosome is a vesicle filled with
enzymes that are capable of breaking down all kinds of organic molecules like carbohydrates, lipids, proteins, and
nucleic acids. They function as the digestive system of the cell. They break down things taken in from outside the
cell, as well as old or worn out components inside the cell. The final difference is found in the size and function of
the vacuole. Although not all animal cells have a vacuole, those that do will have multiple vacuoles to help out with
endocytosis and exocytosis. These are processes that bring materials in and out of the cell. Finally, animal cells tend
to be spherical or irregularly shaped.
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Plant Cells
Plant cells contain two organelles that animals cells do not have: chloroplasts and a cell wall. They also have a third
organelle, a vacuole, that differs from an animal cell vacuole in function and size. Plant cells have a rigid support
structure on the outside of the cell membrane called a cell wall. The cell wall also provides protection. In addition,
plant cells are very important because they can make their own food by using the energy from sunlight and placing
it into chemical bonds in glucose. This process is called photosynthesis. The organelle used to capture sunlight and
turn it into food is the chloroplast. Finally, the vacuole in a plant cell is much larger than the ones found in animal
cells. Each plant cell has one large vacuole that usually takes up 30% to 80% of the cell. Typically the vacuole is
used for storage of either water of waste. Finally, plant cells tend to be rectangular in shape. The strong cell wall
may be a reason for this type of shape.
Vocabulary
centriole: control the movement of the chromosomes during cell division in an animal cell
cell wall: provides structure and support to plant cell
cell membrane: controls what enters and exits the cell, elastic and flexible
chlorophyll: the green pigment found in chloroplasts that traps the sunlight so photosynthesis can occur
chloroplast: the organelle that does photosynthesis
chromosome: coiled strands of DNA
cytoplasm: the jelly-like material found throughout the cell
endoplasmic reticulum: Organelle that is the site of lipid synthesis and protein modification.
Golgi apparatus: Organelle that processes and packages proteins.
lysosome: Organelle of the cell that breaks down and recycles old molecules.
mitochondrion (plural mitochondria): Organelle of the cell in which energy is generated.
nucleus: Cell structure that contains the genetic material, DNA.
organelle: Structure within the cell that has a specific role.
photosynthesis: The process of turning sunlight, water, and carbon dioxide into food (glucose) in the chloroplast of a plant cell
• ribosome: Organelle in which proteins are made (protein synthesis).
• vacuoles: A membrane-bound space within the cell used for storage.
• vesicle: Small membrane-enclosed sac; transports proteins around a cell or out of a cell.
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Summary
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The nucleus stores the genetic information.
The vacuoles are needed for storage.
The lysosomes recycle waste.
The ribosomes produce proteins.
The rough ER is covered with ribosomes and makes proteins, while the smooth ER makes lipids.
The Golgi apparatus packages proteins.
Explore More
Use the resources below to answer the following questions.
• Organelles at http://www.youtube.com/watch?annotation_id=annotation_937748&feature=iv&src_vid=LP7x
Ar2FDFU&v=fKEaTt9heNM (6:25)
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Chapter 1. Cell Organelles in Plant and Animal Cells
MEDIA
Click image to the left or use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/114302
1. What are the functions of the endoplasmic reticulum? What gives the rough endoplasmic reticulum its "rough"
appearance?
2. What are the most abundant organelles in a cell? Where do they occur? What is there function?
3. What is the appearance of the Golgi apparatus? What is the function of the Golgi apparatus?
4. What are lysosomes? What are their functions?
5. What is the function of mitochondria? Do all cells have the same number of mitochondria? How can this
situation be explained?
Explore Even More
• Cell Models at http://www.cellsalive.com/cells/cell_model.htm . Go to this site and click on "animal cell."
1. What are the primary types of protein filaments that make up the cytoskeleton?
2. What is the function of a peroxisome?
3. What is a secretory vesicle? Where are they made? What is their function?
Review
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What is the purpose of the Golgi apparatus?
What is the purpose of the mitochondria?
How is the smooth ER different from the rough ER?
What is a lysosome?
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