Bio 1A Ch. 7

How many ATP and NADH molecules are produced from each molecule of glucose in the citric acid cycle only?

2 ATP, 6 NADH

Which of the following are the final by-products of glucose oxidation during aerobic cell respiration?

ATP, heat, and carbon dioxide

Which compound has the highest free energy and produced the most ATP per molecule when oxidized?

Glucose

In the equation, C6H12O6 + 6O2 --> 6CO2 + 6H2O, ATP and heat would be on which side of the reaction?

The products because this is an exergonic reaction

During the cleavage stage of glycolysis, fructose-1,6 biphosphate is broken down into

Two molecules of glyceraldehyde-3-phosphate

Bacteria that produce nitrite (NO2-) during anaerobic respiration would use ______ as their final electron acceptor.

NO3-

In the citric acid cycle, malate is oxidized to form

Oxaloacetate

Cellular respiration produced the most energy in the form of ATP from which of the following?

Oxidative phosphorylation

In the reaction: pyruvate + CoA + NAD+ --> acetyl CoA + CO2 + NADH, is catalyzed by pyruvate dehydrogenase. If an inhibitor of this enzyme was added to cells _____ levels in the cytoplasm would increase.

Pyruvate

The enzyme responsible for converting pyruvate to acetyl CoA is called

Pyruvate dehydrogenase

In the reaction: pyruvate + CoA + NAD+ --> acetyl CoA + CO2 + NADH, what is oxidized and what is reduced?

Pyruvate is oxidized and NAD+ is reduced

In the citric acid cycle, some intermediates are used in other metabolic reactions. Which of the following adaptations would need to be made by a cell in response to this?

Some oxaloacetate would need to be produced through an alternative pathway to combine with acetyl CoA.

The ATP made during glycolysis is generated by

Substrate-level phosphorylation

During glycolysis, glucose is broken down to

pyruvate

In the citric acid cycle, succinate is oxidized to form

Fumarate

Assuming that the glycerol backbone of a fat molecule can be converted to glyceraldehyde-3-phosphate, an intermediate in glycolysis, how many ATP can be produced from the glycol backbone of a fat molecule?

18

If an athlete is burning glucose only, predict the ratio of oxygen consumed to carbon dioxide that will be produced (C6H12O6 + 6O2 --> 6CO2 + 6H2O)

1:1

How many net ATP and NADH molecules are produced from one molecule of glucose during glycolysis?

2 ATP, 2 NADH

Which of the following are produced during the citric acid cycle?

ATP, NADH, and FADH2

When acetyl-CoA containing radioactively labeled carbon atoms is fed to cells, the CO2 produced is not initially radioactive. However, molecules of citrate and oxaloacetate are radioactive. Only after some time has passed will radioactive CO2 released. What is the best explanation for this observation?

Acetyl groups are not metabolized directly into CO2, but enter a cyclical metabolic pathway.

In a PET scan a patient is injected with radioactively labeled glucose. Why would cancer cells take up more of the glucose than surrounding non-cancerous tissues?

Because they produce more enzymes found in glycolysis.

Which of the following statements is TRUE of both aerobic and anaerobic respiration?

Both use glycolysis to oxidize glucose to pyruvate and both produce NADH as high-energy intermediates.

The equation, C6H12O6 + 6O2 --> 6CO2 + 6H2O (ATP + heat), describes which of the following processes?

Cell respiration

In the citric acid cycle, the acetyl group is removed from acetyl CoA and attached to oxaloacetate to form

Citrate

High-energy electrons from molecules of NADH and FADH2 are transferred to a chain of proteins within the electron transport chain. What is the final protein in the electron transport chain?

Cytochome c

Where does glycolysis take place?

Cytosol

When heart muscles cells are deprived of oxygen, the heart still pumps. What must the heart cells be able to do?

Derive sufficient energy from fermentation

Which of the following do yeast produce during fermentation?

Ethanol

(T/F) During the energy investment phase of glycolysis, glucose has a decrease in free energy.

False

(T/F) Fermentation is more efficient form of energy production then aerobic respiration.

False

(T/F) In prokaryotic cells, the electron transport system occurs in the mitochondria.

False

(T/F) Oxygen is an excellent final electron acceptor because of its low electronegativity.

False

(T/F) Substrate phosphorylation occurs when protons pass through ATP synthase and combine with oxygen to make water.

False

(T/F) The ability of bread to rise is mainly a function of CO2 produced anaerobically during oxidative phosphorylation.

False

(T/F) The aerobic breakdown of glucose yields 34 to 38 ATP, while the anaerobic breakdown yields 20 ATP.

False

(T/F) The proton motive force requires that the H+ concentration is lower in the inter membrane space than inside the matrix.

False

The conversion of pyruvate to acetyl CoA is irreversible. Predict what would happen to fatty acids as a result of this.

Fatty acids cannot be converted into carbohydrates.

The formation of each pyruvate in glycolysis also produced a new of 2 NADH and 2 ATP. However, each metabolism of glucose produces a net of 4 NADH and 4 ATP. How is this explained?

Glucose is cleaved into two 3-carbon sugar that are metabolized into pyruvate

Which of the following processes will occur in the presence or absence of oxygen?

Glycolysis

Some bacteria can use sulfer instead of oxygen as a final electron acceptor. What would they produce during anaerobic respiration?

H2S

Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for the buildup of which molecule?

Lactate

Which occurs only in anaerobic metabolism of glucose?

Lactate fermentation

Where are the protein complexes associated with the electron transport chain located?

Mitochondrial inner membrane

Energy released by the electron transport chain is used to pump H+ ions into which location?

Mitochondrial intermembrane space

In addition to ATP, what are the end products of glycolysis?

NADH and pyruvate

When scientists placed ATP synthase linked to fluorescent actin on a microscope slide and added ATP, the actin could be seen spinning. If the scientist instead added ADP, what would happen?

The actin would not spin because it required ATP hydrolysis.

When scientists placed ATP synthase linked to fluorescent actin on a microscope slide and added ATP, the actin could be seen spinning counterclockwise. If the experiment could be replicated in a cell going through oxidative phosphorylation, what would happen?

The actin would spin clockwise because ATP would be produced instead of hydrolyzed.

Which of the following statement is true?

The citric acid cycle occurs in the mitochondria matrix.

Which of the following statements about the electron transport chain in cell respiration is CORRECT?

The loss in free energy of the electron initially donated NADH is used to transport H+ across the inner mitochondrial membrane against its electrochemical gradient

Which would be TRUE if an inhibitor blocked the activity of mitochondrial ATP synthase?

The pH in the space between the mitochondrial membranes would increase.

If glucose was not phosphorylated in the first few reactions of glycolysis which of the following would occur?

The reactions in glycolysis following the phosphorylation would not be exergonic.

Cancer cells are often in a hypoxic environment, why would this lead to an increase in glucose uptake?

They rely more on glycolysis which is less efficient than oxidative phosphorylation.

The reaction of ethanol fermentation is: pyruvate + NADH --> ethanol + CO2 + NAD+. Why would yeast need to perform this reaction in the absence of oxygen?

To produce NAD+ allowing glycolysis to continue.

(T/F) Glycolysis involves 10 enzyme-catalyzed steps, that can be grouped into three phases: energy investment phase, cleavage phase, and the energy liberation phase.

True

(T/F) If oxygen is present, pyruvate will be converted to acetyl CoA in the mitochondrial matrix.

True

(T/F) Proteins and fats may be used as energy sources to drive aerobic respiration.

True

(T/F) The electron transport chain consists of a series of redox reactions in which electrons are transferred to oxygen as the final electron acceptor.

True

(T/F) When a molecule of NAD+ gains a hydrogen atom, the molecule becomes reduced.

True

If you measure the air a person inhales you observe that the concentrations _______ in the air they exhale.

of O2 falls and CO2 rises