<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
You are reading an older version of this FlexBook® textbook: Human Biology Genetics Teacher's Guide Go to the latest version.

# 6.3: Activities and Answer Keys

Difficulty Level: At Grade Created by: CK-12

## Activity 5-1: Making Protein

### PLAN

Summary Students perform in a play that simulates where and how proteins are made within the cell. They demonstrate the functions of DNA and RNA in the synthesis of protein. Students identify the important functions of proteins in the body, using hemoglobin as an example.

Objectives

Students:

\begin{align*}\checkmark\end{align*} simulate the process of protein synthesis.

\begin{align*}\checkmark\end{align*} identify the roles of DNA, RNA, and amino acids in the synthesis of protein.

\begin{align*}\checkmark\end{align*} explain why proteins are important in the body.

Student Materials

• Activity Report
• Signs:

DNA (GGT-CTC-CTC)

Make Protein Messenger RNA (mRNA)

Transfer RNA (tRNA)/Proline

Transfer RNA (tRNA)/Glutamic Acid 1

Transfer RNA (tRNA)/Glutamic Acid 2

Amino Acid Proline (reverse side: The)

Amino Acid Glutamic Acid 1 (reverse side: Protein)

Amino Acid Glutamic Acid 2 (reverse side: Hemoglobin)

Ribosome (3)

• String or rope
• Resource (Optional)

Teacher Materials

• Resource (Optional)

1. Make signs for each of the roles. If the signs are to be computer-generated, print the roles on 8.5×11\begin{align*}8.5” \times 11”\end{align*} sheets of paper. Staple or glue the sheets onto a piece of construction paper. Color code for roles requiring more than one player, such as tRNA and its corresponding amino acid. An alternative is to print the role names onto colored construction paper.
2. Punch two holes in each sign and attach a piece of string so that the sign can be worn around the player's neck.
3. Prepare a copy of the selected script for each player (10 copies). Highlight each player's part throughout the script. It might be helpful to provide scripts for all members of the class. As an option use the Resource provided as the script.
4. Arrange the string/rope in a large circle to represent the cell membrane. You could also use chalk to represent the cell membrane.
5. Mark off a circle inside the cell to represent the nucleus.
6. Place ribosome signs inside the cell membrane.

Estimated Time One class period

Interdisciplinary Connections

Physical Education or Visual/Performing Arts may have a classroom large enough to accommodate this activity.

Art Create a set of models to simulate protein production within the cell. Use these models to explain the process of protein synthesis to the class.

Language Arts Write a narrative describing the “synthesis of protein.”

Prerequisites and Background

Students should have some knowledge of cell structures involved in protein synthesis. Students should know that proteins are composed of amino acids. Knowledge of the process of protein synthesis is helpful.

Background Information

Review transcription (the process of DNA making mRNA) and translation (the process of mRNA being “read” at the ribosome to form proteins). In this play, Act I simulates transcription (DNA making mRNA). Act 2 simulates translation (mRNA making protein).

mRNA processing (removal of introns and splicing of exons) is omitted from this play as it is a topic better addressed in more advanced classes and high school.

The hemoglobin molecule is a large protein composed of 574 amino acids. This activity refers to a sequence of only three of these amino acids to illustrate how proteins are made.

In the DNA sequence for hemoglobin, if one of the DNA triplets “CTC” mutates to “CAC” then a corresponding change in the mRNA results (“GAG” becomes “GUG”). Instead of glutamic acid, the amino acid valine is introduced. This change of one amino acid is sufficient to alter the shape and consequently the function of the hemoglobin (protein) molecule so drastically that it becomes severely limited in its ability to carry oxygen efficiently. People with this mutation can have sickle-cell anemia, a very serious blood disorder.

• This activity can be done inside or outside the classroom.
• To involve more students, consider having students sit along the cell membrane to view the play or use students instead of string to represent the cell membrane.
• Consider videotaping the play.
• Encourage students to write another play to show how another protein, such as insulin, is formed.
• To illustrate mutations, students can change the sign of the DNA code CTC to CAC. The effect of such a mutation is described in the Background Information.
• Invite students to do research on types of hemoglobin and disorders of hemoglobin resulting in different kinds of anemia such as sickle-cell, pernicious, and Thalassemia.

### IMPLEMENT

Step 1 You may want students to write their own scripts, or you can use the prepared scripts on the Resource.

Step 2 As a class, describe what script will be used. Make copies of the selected script.

Step 3 Arrange a place on the floor for students to make a human marrow cell that produces hemoglobin by placing a string or rope in a large circle to represent the cell membrane. This will become a part of their set as they perform their plays.

Step 4 Cast the students or choose a few students to do the casting. Allow students time to become familiar with their respective roles after receiving the script. Have them practice their roles.

Step 5 After students have completed the procedure described, consider having the students practice and present Acts I and II using several messenger RNAs, transfer RNAs, and amino acids. These presentations should help students learn that protein synthesis occurs simultaneously at many sites within a cell.

Repeat the play, rotating the roles to help students learn how proteins are made.

Make adjustments to the script to double the number of players. Also consider adding codes for other amino acids in hemoglobin.

### ASSESS

Use the script created, performances of the play, research on protein disorders, and written answers on the Activity Report to assess if students can

\begin{align*}\checkmark\end{align*} demonstrate and explain how proteins are synthesized in the cell.

\begin{align*}\checkmark\end{align*} identify the roles of DNA, mRNA, tRNA, and amino acids in the synthesis of protein.

\begin{align*}\checkmark\end{align*} explain why proteins are important in the body.

\begin{align*}\checkmark\end{align*} describe the effects of mutations on protein function.

## Activity 5-1: Making Protein Activity Report Answer Key

• Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.
1. Why are proteins important to the cells in your body? Give examples.
2. What makes one protein different from another?
3. Use words and/or drawings to show that you know how proteins are made in your cells. Include in your answer the following: DNA, mRNA, tRNAs, ribosomes, amino acids, and protein.
4. What do you think would happen if your body incorrectly made a protein, such as hemoglobin?

• Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.
1. What is a protein?
2. What is an amino acid?
3. What are the differences between tRNA and mRNA? Where are they produced and where do they do their work inside the cell?

## Activity 5-1 Resource: Script Making Protein (Student Reproducible)

Instructions to the players are in italics. These lines should not be read aloud.

Act I: A Day in the Life of DNA

Narrator: Proteins are important to the cell. Remember that proteins are made out of building blocks called amino acids. Most of the necessary amino acids are in the food you eat. How are these amino acids put together into the specific proteins your body needs? How do cells in your body make protein, such as hemoglobin?

The answer is through the activities of DNA and RNA in your cells. Let us look at what must happen when DNA tells your cells to make (synthesize) a new protein using amino acids.

Imagine that we can see inside the nucleus and hear what DNA is saying. . .

Scene 1: DNA in the Nucleus

DNA: I am DNA! I carry the code for making proteins including hemoglobin that carries oxygen in your red blood cells. Let us follow the events in the making of the protein hemoglobin inside cells in your bone marrow. Since I am such a big important molecule, I cannot leave the nucleus. Therefore, I will send my code for making hemoglobin with my friend, mRNA. First I make mRNA so it can carry information for hemoglobin. Then I watch while mRNA leaves the nucleus to go out into the cell cytoplasm.

(Holds up a Make Protein sign and reads the message.)

Make Protein.

(DNA turns around and takes hold of one hand of messenger RNA and rotates around. DNA lets go of mRNA's hand. mRNA takes the Make Protein sign from DNA, turns around, and walks out of the nucleus toward one of the ribosomes of the cell.)

Act II: A Day in the Life of Amino Acids

Narrator: Scene 1: mRNA at the Ribosome

mRNA: I am mRNA! I have the coded message from DNA that specifies the order of amino acids necessary to make the protein hemoglobin. Now, I have reached the ribosome, where proteins are actually made. Let's get started making a hemoglobin molecule!

I will demonstrate making part of the protein hemoglobin using only 3 amino acids instead of its 574 required amino acids.

First I need the amino acid proline. Proline's tRNA, where are you?

(tRNA/Proline finds the amino acid Proline. Transfer RNA uses left hand to grab Proline's right hand. tRNA/ Proline holding hands with Proline, goes to the ribosome where messenger RNA is located.)

Proline: Here we are!

mRNA: Come here! I need you now!

(mRNA, with his or her left hand, grabs the right hand of Proline's tRNA.

mRNA swings left hand forward in order to use right hand to grab Proline's left hand. mRNA releases tRNA to leave the ribosome.)

Narrator: Scene 2: mRNA at the Ribosome, looking for Glutamic Acid 1

mRNA: Now I need the amino acid Glutamic Acid. Glutamic Acid 1 and tRNA, where are you?

(mRNA looks around for Glutamic Acid 1 and its tRNA.)

(tRNA/Glutamic Acid 1 finds Glutamic Acid 1. Transfer RNA uses left hand to grab Glutamic Acid 1's right hand. tRNA/Glutamic Acid 1 holding hands with Glutamic Acid 1 goes to the ribosome where messenger RNA is located.)

Glutamic Acid 1: Here we are!

mRNA: Come here! I need you now!

(mRNA with his/her left hand grabs the right hand of Glutamic Acid 1's tRNA.)

Now it is time for the two amino acids to join! Watch the amino acid chain begin!

(mRNA swings left hand forward in order to use right hand to grab Glutamic Acid 1's left hand.

Glutamic Acid 1 tells Proline to let go of mRNA. Glutamic Acid 1 grabs left hand of Proline with the right hand, and mRNA with the left hand.

Glutamic Acid 1 tRNA is free to leave the ribosome.)

Notice that two significant events just happened:

1. Proline has been brought to mRNA by its tRNA.
2. Glutamic Acid has been brought to mRNA by its tRNA and joined to Proline.

Now the amino acid chain is ready to grow!

Narrator: Scene 3: mRNA at the Ribosome, looking for Glutamic Acid 2

mRNA: I am mRNA! I have the coded message from DNA that tells the order of amino acids necessary to make the protein hemoglobin. I have started making hemoglobin, the special protein that helps your blood carry oxygen to cells throughout the body.

It takes hundreds of amino acids to make the one protein. My job is not over. We have more work to do. Now I need another Glutamic Amino Acid. Glutamic Acid 2 and tRNA, where are you?

(mRNA looks around for Glutamic Acid 2 and its tRNA.

tRNA/Glutamic Acid 2 finds Glutamic Acid 2. Transfer RNA uses left hand to grab Glutamic Acid 2's right hand. tRNA/Glutamic Acid 2 holding hands with Glutamic Acid 2 goes to the ribosome where messenger RNA is located.)

Glutamic Acid 2: Here we are!

mRNA: Come here! I need you now!

(mRNA with his/her left hand grabs the right hand of Glutamic Acid 2's tRNA.)

Now it is time for the third amino acid to join the amino acid chain. Watch the amino acid chain grow!

(mRNA swings left hand forward in order to use right hand to grab Glutamic Acid 2's left hand.

Glutamic Acid 2 tells Glutamic Acid 1 to let go of mRNA. Glutamic Acid 2 grabs left hand cf Glutamic Acid 1 with the right hand, and mRNA with the left hand.

Glutamic Acid 2 tRNA is free to leave the ribosome.)

Notice that three significant events have now happened:

1. Proline has been brought to mRNA by its tRNA.
2. Glutamic Acid 1 has been brought to mRNA by its tRNA and joined to Proline.
3. Glutamic Acid 2 has been brought to mRNA by its tRNA and joined to Glutamic Acid 1.

All tRNAs are now available again to find their specific amino acid.

This is how a protein is made! If this protein really was hemoglobin, the protein chain would be made up of 574 amino acids linked together.

Narrator: Scene 4: Completion of the Amino Acid Chain

This process will be continued many times in order to place the 574 amino acids correctly to make the hemoglobin protein.

Now, let's imagine that our protein is finished.

Notice that each tRNA has returned to the cytoplasm to find its complementary amino acid for making another protein.

Also, see how the mRNA is now able to code for another hemoglobin protein.

(mRNA moves to another ribosome, to begin the process again.)

Narrator: Scene 5: Finale

These are only three amino acids of the 574 amino acids required to make the protein hemoglobin!

Proline, Glutamic We are now protein! We are now protein!

Acid 1 and Glutamic Acid 2 (The Amino Acid Group):

(The amino acid group turn over their signs and read their message.)

The Protein Hemoglobin

(After reading their message, they leave the ribosome.)

Narrator: You have just witnessed how DNA makes mRNA and sends mRNA with its code for making protein to the ribosomes. Hemoglobin is only one of thousands of different proteins made by the different cell types in your body.

## Activity 5-1 Report: Making Protein (Student Reproducible)

1. Why are proteins important to the cells in your body? Give examples.

2. What makes one protein different from another?

3. Use words and/or drawings to show that you know how proteins are made in your cells. Include in your answer the following: DNA, mRNA, tRNAs, ribosomes, amino acids, and protein.

4. What do you think would happen if cells in your body incorrectly made a protein, such as hemoglobin?

6 , 7 , 8

## Date Created:

Feb 23, 2012

Apr 29, 2014
You can only attach files to section which belong to you
If you would like to associate files with this section, please make a copy first.