Protein Creation Pathway

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click on the NUCLEUS to begin the tutorial

The Nucleus

The nucleus (flashing circle) is nicknamed the “control center” of a cell. But why? The nucleus contains DNA in its active form and this DNA will ultimately be used as a blueprint to create proteins for use throughout the body. The process of creating a protein begins in the nucleus.

Click the arrow to zoom inside and view a nucleus.

See the dark spot inside the nucleus? This is the nucleolus. Give it a click.

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The Nucleolus

The nucleolus is a dense region within the nucleus. This organelle (tiny cell part) is responsible for creating thousands of ribosomes. Ribosomes play an important role in the creation of proteins as we will see later.

Click the Nucleolus to see an artists drawing.

Nucleus

Nucleolus

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The Nucleolus

The nucleolus is a dense region within the nucleus. This organelle (tiny cell part) is responsible for creating thousands of ribosomes. Ribosomes play an important role in the creation of proteins as we will see later.

These organelles are 3-dimensional. But they often look flat when viewed through a microscope. To proceed, answer the question below.

What are the smaller units that proteins are made from called?

monosaccharide Fatty acid Nucleotide Amino acid

Monosaccharides makes complex

sugars Fatty acids make lipids

Nucleotides make nucleic acids

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Ribosomes

Correct! Amino acids make proteins.

By far, the ribosomes are the most numerous of all organelles. Remember, they are created by the nucleolus. After exiting the nucleus they themselves are responsible for the production of proteins within the cell. Because they are so small, they resemble tiny dots in this picture.

After they exit the nucleus, they are often attached to the endoplasmic reticulum (ER). Click HERE to see the ER and attached ribosomes.

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Ribosomes

By far, the ribosomes are the most numerous of all organelles. Remember, they are created by the nucleolus. After exiting the nucleus they themselves are responsible for the production of proteins within the cell. Because they are so small, they resembles tiny dots in this picture.

After they exit the nucleus, the ribosomes are often attached to the endoplasmic reticulum (ER).

Let’s review. Which organelle creates the ribosomes?

nucleus nucleolus Rough ER

There is something else inside the nucleus

that makes the ribosomes

Ribosomes travel along the rough

ER. They are not created here.

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The Rough Endoplasmic ReticulumCorrect! The nucleolus makes

ribosomes.

Ribosomes are created by the nucleolus and then exit the nucleus. As they exit the nucleus, they begin to create proteins through a process called translation.

The rough ER is called “rough” because it is covered with ribosomes. The rough ER is basically a tunnel system to move ribosomes to other parts of the cell. In this sense, you can compare the rough ER to a subway, and the passengers are the ribosomes.

Click to see the rough ER.

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The Rough Endoplasmic ReticulumRibosomes are created by the

nucleolus and then exit the nucleus. As they exit the nucleus, they begin to create proteins through a process called translation.

The rough ER is called “rough” because it is covered with ribosomes. The rough ER is basically a tunnel system to move ribosomes to other parts of the cell. In this sense, you can compare the rough ER to a subway, and the passengers are the ribosomes.

Since the ribosomes exit the nucleus and flow into the rough ER, the rough ER is attached to the outside of the nucleus.

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The Rough Endoplasmic ReticulumRibosomes are created by the

nucleolus and then exit the nucleus. As they exit the nucleus, they begin to create proteins through a process called translation.

The rough ER is called “rough” because it is covered with ribosomes. The rough ER is basically a tunnel system to move ribosomes to other parts of the cell. In this sense, you can compare the rough ER to a subway, and the passengers are the ribosomes.

Since the ribosomes exit the nucleus and flow into the rough ER, the rough ER is attached to the outside of the nucleus.

See the dots? Those are the ribosomes.

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The Rough Endoplasmic ReticulumRibosomes are created by the

nucleolus and then exit the nucleus. As they exit the nucleus, they begin to create proteins through a process called translation.

The rough ER is called “rough” because it is covered with ribosomes. The rough ER is basically a tunnel system to move ribosomes to other parts of the cell. In this sense, you can compare the rough ER to a subway, and the passengers are the ribosomes.

Since the ribosomes exit the nucleus and flow into the rough ER, the rough ER is attached to the outside of the nucleus.

See the dots? Those are the ribosomes.

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The Rough Endoplasmic ReticulumRibosomes are created by the

nucleolus and then exit the nucleus. As they exit the nucleus, they begin to create proteins through a process called translation.

The rough ER is called “rough” because it is covered with ribosomes. The rough ER is basically a tunnel system to move ribosomes to other parts of the cell. In this sense, you can compare the rough ER to a subway, and the passengers are the ribosomes.

Since the ribosomes exit the nucleus and flow into the rough ER, the rough ER is attached to the outside of the nucleus.

We need to review before we go further.

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Let’s Review

Which step happens first? Click the correct sentence.

How can they exit if they

haven’t been created yet?

1st? -- The ribosomes exit the nucleus

1st? -- The ribosomes begin to make proteins as they travel along the rough ER.

1st? -- The nucleolus creates ribosomesHow can they make proteins if they haven’t been created

yet?Correct! Good

job!

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Click which happens next.

1st = The nucleolus creates ribosomes

2nd? -- The ribosomes exit the nucleus

2nd? -- The ribosomes begin to make proteins as they travel along the rough ER.

Correct!

How can they travel the ER if

they haven’t exited the

nucleus yet?

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Watch the animation. Then click the final step.

1st step: The nucleolus creates ribosomes

2nd step: The ribosomes exit the nucleus

3rd?? -- The ribosomes begin to make proteins as they travel along the rough ER.

Well it was the final choice. I

hope you got it correct.

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Remember, we are tracing the path of protein creation.

1st step: The nucleolus creates ribosomes

2nd step: The ribosomes exit the nucleus

3rd step: The ribosomes begin to make proteins as they travel along the rough ER.

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Protein FunctionsRemember, the ribosomes were

traveling along the rough ER while making proteins. Proteins are used in a wide variety of cell activities, such as growing hair, carrying oxygen, and digesting foods. Many proteins are created by one cell, but needed by another. Therefore many proteins need to be exported. That’s the job of the Golgi Body (named after Camillo Golgi). Click the arrow to see the Golgi Bodies.

The Golgi body receives the proteins that were created by the ribosomes. The Golgi body packages the protein inside a protective envelope called a vesicle.Doesn’t the Golgi body resemble a stack of pancakes?

Be patient after clicking the play button. Let the pictures cycle.

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Vesicles

Vesicles float away from the Golgi body with finished proteins inside. The proteins are released from the cell and are used throughout the body.

Let’s do some review. Use your worksheet to help you with the answers.

1) Which organelle creates ribosomes?

vesicle

nucleus

ribosome

Golgi body

Rough ER

Nucleolus

Vesicles move finished proteins

Ribosomes are made inside the

nucleus by something else

Ribosomes create themselves?

Golgi body packages proteins

Ribosomes travel along the rough ER, but aren’t

made here.

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Review #2

Correct! The nucleolus creates ribosomes.

Which organelle transports the ribosomes from the nucleus to the Golgi body?

vesicle

nucleus

ribosome

Golgi body

Rough ER

Nucleolus

Golgi body packages proteins

The nucleus holds DNA

The nucleolus makes ribosomes

Vesicles move finished proteins

Ribosomes make proteins

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Review #3

Correct! The rough ER transports the ribosomes .

Which organelle creates proteins?

vesicle

nucleus

ribosome

Golgi body

Rough ER

nucleolus

The Golgi body packages proteins

The nucleus holds DNA

The nucleolus makes ribosomes

Vesicles move finished proteins

The rough ER transports ribosomes

around the cell

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Review #4

Correct! Ribosomes make proteins.

Which organelle packages finalized proteins for shipment?

vesicle

nucleus

ribosome

Golgi body

Rough ER

Nucleolus

The ribosome makes proteins

The nucleus holds DNA

The nucleolus makes ribosomes

Vesicles move finished proteins

The rough ER transports ribosomes

around the cell

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Review #5

Correct! The Golgi body packages finalized proteins for shipment.

Which organelle protects a finished protein as it exits the cell?

vesicle

nucleus

ribosome

Golgi body

Rough ER

Nucleolus

The Golgi body packages proteins

The nucleus holds DNA

The nucleolus makes ribosomesRibosomes make

proteins

The rough ER transports ribosomes

around the cell

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Review #6

Correct! The vesicle protects a finished protein as it exits the cell

Now click on the nucleolus.

Try again. This is the rough ER..

Try again. This is the Golgi body.

Try again. This is the mitpchondria.

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Review #7

Correct! That was the nucleolus.

Now click on the Golgi body…remember pancakes?

Try again. This is the flagella..

Try again. This is the mitochondria.

Try again. This is the rough ER.

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Review #8

Correct! That was the Golgi body.

Now click on the rough ER.

Try again. This is the Nucleolus

Try again. This is the mitochondria.

Try again. This is the Golgi body.

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Review #9

Correct that was the rough ER!

Now click on the organelle that packages proteins for shipment outside of the cell.

Try again. The rough ER does not do this.

Try again. The nucleolus does not

do this.

Try again. The mitochondria does

not do this.

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Review #10

Correct! That was the Golgi body.

Now click on the organelle that creates ribosomes.

Try again. The mitochondria does

not do this.

Try again. The rough ER does not do this.

Try again. The Golgi body does not do

this.

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Correct! That was the nucleolus.

I hope this tutorial was helpful. This will be posted on my website for you to review at any time. Turn in your handout. Feel free to start over if you would like to do some review.

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