17.3: Lab Report

Part 1: DNA to Protein Exercise

The following DNA sequence is part of the gene that controls dimples. Decode the DNA message into mRNA, tRNA and finally amino acids. Use the genetic code chart to fill in the table below.

Note

The genetic code is based on mRNA (not DNA or tRNA). When you have finished this, you will be able to determine the phenotype of the person the DNA came from. (If arginine is the 3rd amino acid, the person will have dimples.)

Data Table for Codons, Anticodons, and Amino Acids

DNA	mRNA Codon	tRNA Anticodon	Amino Acid
C G A
G T C
G C A
T A A

1. Does the person with the sequence above have dimples?

 

2. What two great tasks (the central dogma of molecular biology) are carried out by our genetic machinery?

 

3. What name do we call a three-nucleotide sequences of mRNA?

 

4. How many DNA bases does it take to code for an RNA codon?

 

5. How many amino acids does an RNA codon code for?

 

6. What brings amino acids to the ribosome?

 

7. What is the difference between transcription and translation?

 

8. True or false (circle one): Most of the DNA in the human genome codes for proteins.

Part 2: Protein Synthesis Exercise

DNA: 3′ A G C C G T A G A A T T 5′

1. Using this strand of DNA as a template, draw a picture of the complete DNA molecule. Include all parts of the DNA molecule. You do not need to draw your molecule with atomic accuracy.

 

 

 

 

 

 

 

 

 

2. Now draw a complete picture of the mRNA strand that will be made from this DNA. Label the 5′ and 3′ ends of your mRNA strand. (Use the given DNA strand at the top of this page as your template . . .)

 

 

 

 

 

 

 

 

 

3. Using the space below, carefully indicate the codons present in the mRNA strand from question 2.

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Using the space below question 3 (above), draw a complete picture of all the tRNA molecules that will match up with the codons from the previous question. Include all appropriate amino acids in your picture, and do not mix up their order!

5. Using the space below question 3 (but below the tRNA-amino acid complexes), draw a picture of the completed protein coded for by this strand of DNA (three letter abbreviations are fine). Show the amino acids in the same order they would be observed in the finished protein.

Part 3: Protein Synthesis Bingo

Fill in the boxes with 16 of the 20 amino acids. Every bingo square will be unique. Then listen as random nucleotide sequences are pulled from the hat. Listen carefully to what kind of sequence is called! Use the mRNA codon chart on the previous page to determine the amino acid associated with each sequence. (Printable version here.)

Table of Amino Acids

alanine—ala—A	cysteine—cys—C	histidine—his—H	methionine—met—M	threonine—thr—T
arginine—arg—R	glutamine—gln—Q	isoleucine—ile—I	phenylalanine—phe—F	tryptophan—trp—W
asparagine—asn—N	glutamic acid—glu—E	leucine—leu—L	proline—pro—P	tyrosine—tyr—Y
aspartic acid—asp—D	glycine—gly—G	lysine—lys—K	serine—ser—S	valine—val—V

Data Table for Codons and AAs

	Sequence Called	DNA? mRNA? tRNA?	Codon	AA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

Licenses and Attributions

CC licensed content, Original

• Biology Labs. Authored by: Wendy Riggs. Provided by: College of the Redwoods. Located at: http://www.redwoods.edu. License: CC BY: Attribution

CC licensed content, Shared previously

• 0322 DNA Nucleotides. Provided by: OpenStax. Located at: http://cnx.org/content/col11496/1.6. License: CC BY: Attribution
• Central Dogma of Molecular Biochemistry with Enzymes. Authored by: Dhorspool. Located at: https://commons.wikimedia.org/wiki/File:Central_Dogma_of_Molecular_Biochemistry_with_Enzymes.jpg. License: CC BY-SA: Attribution-ShareAlike

Public domain content

• The completed chart of the genetic code. Provided by: National Institutes of Health. Located at: http://history.nih.gov/exhibits/nirenberg/HS5_cracked.htm. License: Public Domain: No Known Copyright