Gene ExpressionAnd Inheritance

Introductory Take Home Assignment

Due Date: Tuesday, April 2nd

Name: ___________________

Biology Name

Vocabulary List – RNA and Protein Synthesis

Read Sections 13.1 and 13.2 in your textbook to complete the two matching sections below. Each definition is used only once.

13.1 RNA

Term Definition

_____1. RNA a. Forms an important part of both subunits of the ribosome.

_____2. Messenger RNA b. Portions that are cut out and discarded from pre-mRNA molecules while they are still in the nucleus, before they can go into action.

_____3. Ribosomal RNA c. Carries instructions for polypeptide synthesis from nucleus to ribosomes in the cytoplasm.

_____4. Transfer RNA d. Regions of DNA that have specific base sequences that act as signals to show RNA polymerase exactly where to begin making RNA.

_____5. Transcription e. Process during which segments of DNA serve as templates to produce complementary RNA molecules.

_____6. RNA polymerase f. Carries amino acids to the ribosome and matches them to the coded mRNA message.

_____7. Promoters g. An enzyme that binds to DNA during transcription, separates the DNA strands, then uses one strand of DNA as a template from which to assemble nucleotides into a complementary strand of RNA.

_____8. Intron h. Abbreviation for ribonucleic acid, a type nucleic acid that, like DNA, consists of a long chain of nucleotides.

_____9. Exon i. Portions of the pre-mRNA molecule that remain after introns are removed; these get spliced together to form the final mRNA

Over

13.2 Ribosomes and Protein Synthesis

Term Definition

_____10. Polypeptide a. The “language” of DNA made up of just four “letters”: A, C, G, and U. This code is read three “letters” at a time to code for the amino acids necessary to build a polypeptide.

_____11. Genetic Code b. Each three-letter “word” in mRNA; consists of three consecutive bases that specify a single amino acid to be added to the polypeptide chain.

_____12. Codon c. Set of three unpaired bases (complementary to one mRNA codon) found on a tRNA molecule.

_____13. Translation d. The way in which DNA, RNA, and proteins are involved in putting genetic information into action in living cells.

_____14. Anticodon e. The decoding of an mRNA message into a protein.

_____15. Gene Expression f. A long chain of amino acids linked by peptide bonds.

Biology Name

In your online textbook (www.biology.com), login and use the ‘Explore’ function to naviate to the Activities tab for 13.2.

Part 1. InterActive Art: Protein Synthesis

Follow the instructions on the screen and press the play button to watch an animation of the steps of Protein Synthesis. Fill in the blanks below based on the narrative that accompanies the animation.

DNA

a) Which molecule contains coded instructions that control the production of proteins in a cell?

b) What do we call the first step of decoding these instructions?

c) Name the molecule that serves as a copy of part of the DNA sequence.

Transcription

a) Name the enzyme that separates DNA strands and builds RNA.

b) Which molecule acts as a template – DNA or RNA?

c) What is the abbreviation for ‘messenger ribonucleic acid’?

The Ribosome

a) What will be built by joining together amino acids based on the sequence of nucleotides in mRNA?

b) Name the structure found in the cytoplasm that is responsible for helping interpret these instructions.

Translation

a) The attachment of mRNA to a ribosome marks the onset of what step?

b) Give the three-letter mRNA sequence that is called the start codon.

c) What type of RNA enters the ribosome and binds with the complementary mRNA codon?

d) A complementary sequence of three bases on a tRNA is called an

e) What protein-building monomer is carried by each tRNA?

Completing the Polypeptide

a) The polypeptide continues to grow until it reaches what on the mRNA?

b) How many amino acids are in the completed polypeptide shown in the animation?

Name: Date: Period:

From DNA to Protein

Go to the following website:

http://www.yourgenome.org/teachers/dnaprotein.shtml

Scroll Down until you see the button below -CLICK IT!

You will explore how the instructions encoded within DNA are used to produce proteins, the molecular machines that build and control our cells.

When the animation appears – CLICK START

Part 1 – DNA and GenesDirections: Read screens 1-4 and answer the following questions.

1. The _____________________ is at the center of most HUMAN cells (where DNA is found)

2. Define chromosomes: __________________________________________________________________________________________________________________________________________________________________________________________________

3. Humans contain _________chromosomes. Two of which are ______________________________________________Females have ____ ____ and Males have ____ ____

Part 2 – Making RNA Directions: Read screens 1-5 and answer the following questions.

1. _____________ are coded instructions for the production of proteins or RNA molecules, sections of the strands of DNA.

2. Where can you find a SIGNAL for the start/finish of the instructions?__________________

3. How does a gene get “SWITCHED ON”?

4. How do transcription factors arrive?

What kinds of proteins take part in the process? __________________ and ____ ___________

What are their functions?

5. Describe the process seen on screen 4.

What is this process called?

6. What is RNA made of?

Explain the complementary base pairing that occurs on screen 5.

Part 3 – Processing RNA Directions: Read screens 1-4 and answer the following questions.

1. What needs to occur before the RNA can be used as a template for the production of proteins? _______________________________________________________________

What is added to each end of the RNA?

2. What is getting removed on screen 3? ____________________________

What is the process called? ________________________________________

3. Explain the final product and what it is ready for.

Part 4 – Making Proteins Directions: Read screens 1-4 and answer the following questions.

1. What is the molecule pictured below called?

Explain their function:

2. Each _______________ has a ____________ letter code that is matched with the RNA in the ribosome.

3. Describe what is happening on screens 3-4.

Part 5 – Folding Proteins Directions Read screens 1-2 and answer the following questions.

1. How are proteins considered functional? What needs to happen?

2. What is the example chosen in the animation? ___________________________

It is a single chain of ____________ Amino Acids.

Biology Name ___________________________________

How do genes code for proteins? It is like deciphering a code. Use the following key to unlock the meaning of the sentence.

A B C D E F G H I J

K L M N O P Q R S T

U V W X Y Z

.___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___.

How does this relate to DNA and its coding for proteins? Use the following chart to decipher the DNA code below building a polypeptide.

DNA Triplet

CAA CTT TAC CAT GTT ACG TTA

Amino Acid name

Valine Glutamic acid

Methionine Alanine Glycine Cytosine Aspartic acid

DNA Code: TAC GTT CAA CTT GTT ACG TTA

Biology Name

Decoding DNA

Part 1. Code Cracking…Pick any TWO sequences to decode (choose from: chimp, human, flesh eating microbe, sweet orange). Circle your two choices.

At the following website, find the section called “Function Finder”. http://www.yourgenome.org/downloads/activities.shtmlClick the third option in the list in that box, called “Codon Cracker with Function Finder”.

You will use the CODON CRACKER to decode the two sequences you chose above.

Over

Transcribed Sequence (mRNA):C A U A A A C A C C A U U U G G G U C A C

Transcribed Sequence (mRNA):A G A C U C A A G A A U G A A G C U U C C

Transcribed Sequence (mRNA):G U U G U C A C U A A A U C C A A U G U G

Transcribed Sequence (mRNA):A C G A U G U C A A C G A C A A C A A C C

FOR EACH OF YOUR TWO CHOICES, FOLLOW THESE STEPS:

1. Write the DNA and mRNA code from your two choices into the rows in the tables below.2. Go to the Codon Cracker website above. You will crack the code using the Transcribed Sequence (mRNA) and be sure to click the corresponding button on the screen RNA. 3. Begin translation by entering the first three bases from your RNA code using your mouse to click A, C, T, or G. Then, click “Translate”. You should see the name of the amino acid that was coded by that set of three bases.4. Click “Add to Chain” to start building your polypeptide chain on the screen.5. Once your Polypeptide is complete, copy the line that says “Amino Acid Chain (3 Letter)” into the table below.6. Look through choices A - D below and find the amino acid chain that you just decoded. Write the matching letter for the name/description of that protein in the last box of the table.

Choice 1 - Organism Name: DNA Sequence

Transcribed mRNA SequenceAmino Acid Chain (3 letter)

Name/Description of Protein – Write the letter of the choice on the next page that matches the code you cracked.

Choice 2 - Organism Name:

DNA Sequence

Transcribed mRNA SequenceAmino Acid Chain (3 Letter)

Name/Description of Protein – Write the letter of the choice on the next page that matches the code you cracked.

Over

Name/Descriptions of Proteins:

a. Amino Acid Sequence: Val – Val – Thre – Lys – Ser – Asn - ValPart of the gene that codes for an enzyme called sialidase. When these bacteria infect an animal they secrete sialidase to break-down the animal’s tissues, enabling them to spread through its body.

b. Amino Acid Sequence: Hist – Lys – Hist – Hist – Leu – Gly - HistTaken from the gene that codes for granulysin. Granulysin is a toxic protein that is released by immune cells in response to infection, to kill pathogens like bacteria.

c. Amino Acid Sequence: Arg – Leu – Lys – Asn – Glut.Acid – Ala - SerPart of the OCA2 gene sequence. The OCA2 gene codes for a proteincalled the P protein which is involved in pigmentation. Variation in its sequence is a major influenceon whether we have brown or blue eye color.

d. Amino Acid Sequence: Thr – Meth – Ser – Thr – Thr – Thr - ThrSequence taken from the gene that codes for pectinesterase. Pectinesteraseis an enzyme that helps to break down cell walls and soften tissues during the process of ripening.

This activity modified from the original found here: http://www.yourgenome.org/downloads/pdf/teachers/seq/FT_sequence_bracelets.pdf

Part 2. deCODE: What's your name in DNA?

Now go to this website (best performance with Google Chrome):

http://www.ebi.ac.uk/cgi-bin/decode/decode.cgi

Type in any single word (a first name, or any other single word of your choice) in the box.

What is the name/word that you typed in? (For security, please don’t use your full name.)

Click “deCode”. Write your personalized decode results. Name = ______________________

The letters of your name have been changed to the closest DNA bases. Write your name/word in DNA letters as it appears on the screen:

The website searched for a protein which closely matched your personalized sequence. What were the results of that search?

WHERE DO THE STEPS OF GENE EXPRESSSION OCCUR?

Label each *’d box with the correct Organelle/Cell Structure, and label each numbered box with the correct step of Gene expression. Use your textbook if needed.

A. Proteins are assembled from mRNA on a ribosome (translation)B. Vesicles containing proteins are shipped to their final destination, in or out , of the cell C. mRNA travels to the cytoplasmD. Newly made proteins are carried from the Rough ER to the Golgi apparatus E. Proteins are modified further , then sorted and packagedF. mRNA is transcribed from DNA

G. Proteins that will be exported from the cell membrane or sent to specialized locations in the cell complete assembly on ribosomes bound to the Rough ER

Organelles/Cell Structures:Cell Membrane Golgi Apparatus Nucleus Rough ERVesicle Smooth ER Cytoplasm Nuclear Membrane

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