In the Classroom
Electron Transport Wordsearch Terry L. Helser Department of Chemistry and Biochemistry, SUNY College at Oneonta, Oneonta, NY 13820-4015;
[email protected] This puzzle contains 41 names, terms, and acronyms that describe electron transport and oxidative phosphorylation. Discover them by filling the blanks in the description below the letter matrix. Then, find and highlight these items in the letter matrix. (Hint: there are no words within words.) All underlined letters, and only those, are found in the matrix. “ELECTRON” is already done for you. Afterward, use the 21 letters remaining in the matrix to complete the sentence describing these pathways. Your success will be rewarded. The answers to the Electron Transport Wordsearch are on the following page. Good hunting!
The E L E C T R O N _ _ _ _ _ _ _ _ _ chain or ETC is on and in the C _ _ _ _ _ _ of a M _ _ _ _ _ _ _ _ _ _ _ _ . To start, N _ _ _ is oxidized to _ _ _ in C _ _ _ _ _ _ I by reducing _ _ _ . Similarly, the _ _ _ _ 2 is oxidized by a F _ _ _ _ _L _ _ _ _ _ D _ _ _ _ _ _ _ _ _ _ _ _ to FAD in complex II. Both complexes contain I _ _ _ -S _ _ _ _ _ centers that in turn reduce C _ _ _ _ _ _ _ Q (_ _ or _ _ _). It transfers electrons to complex III which passes them to C _ _ _ _ _ _ _ _ _ O _ _ _ _ _ _ (complex IV) where they pass through cyt a heme _ _ and C _ _ _ _ _ (_ _) ions. Cyt a3 then reduces O _ _ _ _ _ to W _ _ _ _ . The energy released pumps P _ _ _ _ _ S across the inner M _ _ _ _ _ _ _ to the I _ _ _ _ _ _ _ _ _ _ _ _ S _ _ _ _, making it A _ _ _ _ _ and the M _ _ _ _ _ B _ _ _ _, according to the Mitchell C _ _ _ _ _ _ _ _ _ _ _ theory. This _ _ and charge gradient then drives O _ _ _ _ _ _ _ _ P _ _ _ _ _ _ _ _ _ _ _ _ _ _ by the L _ _ _ _ _ _ _ shaped, ATP S _ _ _ _ _ _ _ complex. The synthesis of _ _ _ from _ _ _ in the _ _ subunit can be uncoupled from the ETC by dinitrophenol (_ _ _ ), a deadly diet aid. (How many other words of three or more letters can you find?) Use the remaining letters to fill in the following sentence:
_ _ _ _ _
_ _ _ _ _ _ _ _ _
_ _ _
_ _ _ _ .
JChemEd.chem.wisc.edu • Vol. 80 No. 4 April 2003 • Journal of Chemical Education
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In the Classroom Answers to the Electron Transport Wordsearch
The ELECTRON TRANSPORT chain or ETC is on and in the CRISTAE of a MITOCHONDRION. To start, NADH is oxidized to NAD in COMPLEX I by reducing FMN. Similarly, the FADH 2 is oxidized by a FLAVIN-LINKED DEHYDROGENASE to FAD in complex II. Both complexes contain IRON-SULFUR centers that in turn reduce COENZYME Q (UQ or CoQ). It transfers electrons to complex III which passes them to CYTOCHROME OXIDASE (complex IV) where they pass through cyt a heme Fe and COPPER (Cu) ions. Cyt a3 then reduces OXYGEN to WATER. The energy released pumps PROTONS across the inner MEMBRANE to the INTERMEMBRANE SPACE, making it ACIDIC and the MATRIX BASIC, according to the Mitchell CHEMIOSMOTIC theory. This pH and charge gradient then drives OXIDATIVE PHOSPHORYLATION by the LOLLIPOP shaped, ATP SYNTHASE complex. The synthesis of ATP from ADP in the F1 subunit can be uncoupled from the ETC by dinitrophenol (DNP), a deadly diet aid.
REDOX REACTIONS RUN LIFE.
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Journal of Chemical Education • Vol. 80 No. 4 April 2003 • JChemEd.chem.wisc.edu
