Gen Bio C.9
Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products?
2 NADH, 2 pyruvate, and 2 ATP
Approximately how many molecules of ATP are produced from the complete oxidation of one molecule of glucose (C6H12O6) in aerobic cellular respiration?
30-32
In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules?
ATP, CO2, and ethanol (ethyl alcohol)
Which of the summary statements below describes the results of the following reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy C6H12O6 is oxidized and O2 is reduced
Even though plant cells carry out photosynthesis, they still use their mitochondria for oxidation of pyruvate. Under what conditions will plant cell mitochondria be active in this process?
In all cells, with or without light
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms
In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?
It increases the surface for oxidative phosphorylation
Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction?
It loses electrons and loses potential energy
Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction?
It loses electrons and loses potential energy.
Which of the following statements about NAD+ is true?
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle
Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules?
NADH
If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure?
Oxaloacetate will accumulate and citric acid will decrease
What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction?
The glucose molecule is oxidized.
If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production?
The rates of ATP production and carbon dioxide production would both increase
Why are carbohydrates and fats frequently considered high-energy foods?
They contain many electrons associated with hydrogen atoms
Fatty acids usually have an even number of carbons in their structures. Catabolism of fatty acids produces two-carbon fragments that are converted to acetyl CoA molecules. What is the most likely way in which these acetyl CoA molecules would be metabolized in aerobic cellular respiration?
They would directly enter the citric acid cycle
The oxygen consumed during cellular respiration is directly involved in which of the following processes or events?
accepting electrons at the end of the electron transport chain
What kinds of cells carry out ATP synthesis by chemiosmosis?
all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors
The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?
coupling of an endergonic reaction to an exergonic reaction
Yeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy?
glucose
Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration?
glucose → NADH → electron transport chain → oxygen
Which of the following metabolic processes normally occurs regardless of whether or not oxygen (O2) is present?
glycolysis
Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?
glycolysis and fermentation
Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?
mitochondrial intermembrane space
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
oxidation of pyruvate to acetyl CoA and the citric acid cycle
Which of the following processes is driven by chemiosmosis?
oxidative phosphorylation\
Which of the following processes generates a proton-motive force in mitochondria?
pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes ________
reduced
-During which of the following metabolic processes is most of the CO2 from the catabolism of glucose is released?
the citric acid cycle
Which of the following events takes place in the electron transport chain?
the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle
In glycolysis, for each molecule of glucose oxidized to pyruvate, ________
two molecules of ATP are used, and four molecules of ATP are produced
If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in oxidation of pyruvate to acetyl CoA?
⅓
