In the Classroom
Genetic Code Wordsearch Terry L. Helser Department of Chemistry and Biochemistry, SUNY College at Oneonta, Oneonta, NY 13820-4015;
[email protected] This puzzle contains 30 words that describe the nucleotide sequences used to produce proteins in all terrestrial organisms. Also included are six acronyms for the nucleic acids directing this process. Discover them by filling the blanks in the description below the matrix. Then, find and highlight these items in the letter matrix. (Hint: words can be read vertically, horizontally, or diagonally. Both singular and plural forms are possible.) The words “GENETIC CODE” have been done for you. Use the remaining letters to complete the sentence describing one “secret of life”. Your success will be rewarded. The answers to the Genetic Code Wordsearch are on the following page. Good hunting!
The G E N E T I C C O D E is the set of 64 C _ _ _ _ _, each with T _ _ _ _ N _ _ _ _ _ _ acid B _ _ _ s, that specify the A _ _ _ _ A _ _ _s in proteins. It is U _ _ _ _ _ _ _ _ and D _ _ _ _ _ _ _ _ _ (codon # > amino acid #). The _ _ _ codon tells the R _ _ _ _ _ _ _ where to start the T _ _ _ _ _ _ _ _ _ _ of an m _ _ _, while three _ _ _ _ codons (UAA, _ _ _ , and _ _ _ ) signal T _ _ _ _ _ _ _ _ _ _ in all known cells. Between these two signals is an _ _ _ _ _______
_ _ _ _ _ (ORF), where a C _ _ _ _ _ _ _ _ _ series of C _ _ _ _s selects the correct A _ _ _ _
_ _ _ _ -t_ _ _s by pairing with their _ _ _ _codons. W _ _ _ _ _ allows more than one codon to select the same tRNA. _ _ _ base substitutions that produce S _ _ _ _ _ or M _ _ _ _ _ _ _ M _ _ _ _ _ _ tend to C _ _ _ _ _ _ _ the protein’s function, while N _ _ _ _ _ _ _ mutations do not. I _ _ _ _ _ _ _ _ or D _ _ _ _ _ _ _ of bases in an ORF cause F _ _ _ _ _ _ _ _ _ M _ _ _ _ _ _ _s if the number is not divisible by three. Use the remaining letters to fill in the following sentence: Life is a
_ _ _ _ _ _ _ _
of
_ _ _ _ _ _.
JChemEd.chem.wisc.edu • Vol. 80 No. 4 April 2003 • Journal of Chemical Education
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In the Classroom Answers to the Genetic Code Wordsearch
The GENETIC CODE is the set of 64 CODONS, each with THREE NUCLEIC acid BASEs, that specify the AMINO ACIDs in proteins. It is UNIVERSAL and DEGENERATE (codon # > amino acid #). The AUG codon tells the RIBOSOME where to start the TRANSLATION of an mRNA, while three STOP codons (UAA, UGA, and UAG) signal TERMINATION in all known cells. Between these two signals is an OPEN READING FRAME (ORF), where a CONTINUOUS series of CODONs selects the correct AMINO ACYL-tRNAs by pairing with their ANTIcodons. WOBBLE allows more than one codon to select the same tRNA. DNA base substitutions that produce SILENT or MISSENSE MUTANTS tend to CONSERVE the protein’s function, while NONSENSE mutations do not. INSERTION or DELETION of bases in an ORF cause FRAMESHIFT MUTATIONs if the number is not divisible by three.
Life is a SEQUENCE of CODONS
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Journal of Chemical Education • Vol. 80 No. 4 April 2003 • JChemEd.chem.wisc.edu
