2. A biochemist wanted to study how various substanceswere used in cellular respiration. In one experiment, she allowed amouse to breathe air containing O2 \"labeled\" by a particularisotope. In the mouse, the labeled oxygen first showed up in
a. ATT.
b. NADH
C. CO2
d. H2O
3. A gram of fat produces _____ as much ATP as a gramof glucose.
a. two times
b. three times
c. four times
d. five times
4. The intermembrane space of mitochondria has a largeconcentration of
a. FADHz.
b. hydrogen ions.
C. NAD
d. oxygen
5. During pyruvate oxidation, a carboxyl group isfirst removed before NAD+ is reduced to NADH. Which of thefollowing molecules does the oxidized two-carbon molecule combinewith to produce the final substrate?
a. acetyl CoA
b. coenzyme A
C. pyruvate dehydrogenase
d. succinate
6. Which of the following is a true distinctionbetween cellular respiration and fermentation?
a. NADH is oxidized by passing electrons to the electron transportchain in respiration only.
b. Only respiration oxidizes glucose.
C. Substrate-level phosphorylation is unique to fermentation;
cellular respiration uses oxidative phosphorylation.
d. Fermentation is the metabolic pathway found inprokaryotes;
cellular respiration is unique to eukaryotes.
