Unit 3.2 Cellular Respiration

1. Glycolysis is an _ reaction

• Exergonic

• Endothermic

• Unregulated

• Endergonic

Pyruvate is formed

• on the inner mitochondrial membrane

• in the mitochondrial matrix

• in the nucleus

• in the cytosol

Most of the energy that enters electron transport enters as 

• ATP 

• glucose. 

• CO2. 

• FADH2 and NADH.

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is

• the oxidation of glucose and other organic compounds.

• the flow of electrons down the electron transport chain.

• the H+ concentration gradient across the inner mitochondrial membrane.

• the affinity of oxygen for electrons.

The final electron acceptor of the electron transport chain that functions in oxidative phosphorylation is

• oxygen 

• Water

• Pyruvate

• ADP

 In the presence of a metabolic poison that specifically and completely inhibits all functions of mitochondrial ATP synthase, which of the following would you expect? 

• a decrease in the pH (H+ concentration) difference across the inner mitochondrial membrane

• an increase in the pH (H+ concentration) difference across the inner mitochondrial membrane

• Increased synthesis of ATP

• an accumulation of NAD+

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

• ATP synthase pumps protons by active transport.

• FADH2 is oxidized.

• The protein complexes I-IV phosphorylate ADP to form ATP.

• The electrons gain free energy.

Most CO2 from catabolism is released during

• electron transport.

• the citric acid cycle. 

• glycolysis. 

• lactate fermentation. 

In the 1940s, some physicians prescribed low doses of a drug called dinitrophenol (DNP) to help patients lose weight. This unsafe method was abandoned after a few patients died. DNP uncouples the chemiosmotic machinery by making the lipid bilayer of the inner mitochondrial membrane leaky to H+. What impact does this have on ATP production?

• reduces oxidative level phosphorylations

• reduces substrate level phosphorylations

• This would have no impact on ATP production.

• increases substrate level phosphorylations

Cyanide is a poison that blocks the passage of electrons along the electron transport chain. Which of the following is a metabolic effect of this poison? 

• Alcohol would build up in the cells

• Electrons are passed directly to oxygen, causing cells to explode.

• No proton gradient would be produced, and ATP synthesis would cease.

• The lower pH of the intermembrane space is much lower than normal.