Question

1. Match each statement about pyruvate metabolism in mitochondria with the correct term.

   This product of pyruvate oxidation directly supplies energy to the mitochondrial electron transport system.    This product of pyruvate oxidation diffuses across the lipid bilayer of the  mitochondrial inner membrane. This product of pyruvate oxidation enters the citric acid cycle.    This is co-transported into the mitochondrial matrix along with pyruvate.

   A. NADH B. AcetylCoA C. CO2 D. H+

QUESTION 14

1. You have a small plastic chamber with a semipermeable cellulose membrane running down the middle. This membrane contains pores that allow molecules with sizes under 10,000 daltons (Da) to pass freely. You fill one side of your chamber with water (18 Da) and the other side with an equal volume of solution containing bromophenol blue dye (670 Da) at a concentration of 4 mg/mL in water. After allowing your experimental chamber to stand overnight, you would expect to find ____________________.

   		that all the water in the chamber had moved to the side you added dye to, which was hyperosmotic
   		4 mg/mL bromophenol blue solution on both sides of the membrane due to diffusion of the molecules.
   		that all the dye had moved to the opposite side of the membrane, which was hypoosmotic
   		2 mg/mL bromophenol blue solution on both sides of the membrane due to diffusion of the molecules.

QUESTION 15

1. Fermentation pathways ____________________.

   		include an electron transport system in which molecular oxygen is not the final acceptor
   		produce less ATP and more NADH than glycolysis
   		cannot operate if molecular oxygen (O2) is present
   		produce ATP only through glycolysis, and regenerate NAD+

Answer 1

13. This product of pyruvate oxidation directly supplies energy to the mitochondrial electron transport system = A. NADH
Pyruvate + NAD+ + CoASH ------> Acetyl CoA + NAD+ + CO2

This product of pyruvate oxidation diffuses across the lipid bilayer of the mitochondrial inner membrane = C. CO2
One molecule of CO2 is produced per pyruvate during the transition reaction.

This product of pyruvate oxidation enters the citric acid cycle = B. AcetylCoA
The product of pyruvate oxidation = Acetyl CoA

This is co-transported into the mitochondrial matrix along with pyruvate = D. H+
Pyruvate is symported into the mitochondria along with H+


14. Answer: Option D is correct
Explanation:
The membrane is permeable to both water and bromophenol blue molecules. So, 2 mg/mL bromophenol blue solution on both sides of the membrane due to diffusion of the molecules can be observed.

15. Answer: Option D is correct
Explanation:
The main function of fermentation is to regenerate NAD+ so that glycolysis can continuously occur under anaerobic conditions.