Chapter 9 Mastering Biology
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?
pyruvate, ATP, and NADH
Which of the following describes the process of glycolysis
It represents the first stage in the chemical oxidation of glucose by a cell
Which of the following statements best describes the primary role played by oxygen in cellular respiration?
It serves as the final acceptor for electrons from the electron transport chain.
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
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
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
anion and cation
In chemiosmosis, what is the most direct source of energy that is used to convert ADP +Pi to ATP?
energy released from movement of protons through ATP synthase, down their electrochemical gradient
Where are the proteins of the electron transport chain located?
mitochondrial inner membrane
Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?
mitochondrial intermembrane space
What molecule is indicated by the letter D?
oxygen
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
What process occurs within Box B?
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
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?
1/3
How many NADH are produced by glycolysis?
2
In glycolysis there is a net gain of _____ ATP.
2
Which of the following statements is not true of most cellular redox reactions?
A hydrogen atom is transferred to the atom that loses an electron
In glycolysis, what starts the process of glucose oxidation?
ATP
How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.)
Both electron transport and ATP synthesis would stop
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
Which term describes the degree to which an element attracts electrons?
Electronegativity
Which of these is NOT a product of glycolysis?
FADH2
NADH and FADH2 are both electron carriers that donate their electrons to the electron transport chain. The electrons ultimately reduce O2 to water in the final step of electron transport. However, the amount of ATP made by electrons from an NADH molecule is greater than the amount made by electrons from an FADH2 molecule.
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor
Gaseous hydrogen burns in the presence of oxygen to form water: 2H2 + O2 → 2H2 O + energy Which molecule is oxidized and what kind of bond is formed?
Hydrogen, polar
What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?
Ionic
Which of the following statements is true of the bonds in a water molecule?
Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero
What happens when electrons are passed from one atom to a more electronegative atom?
The more electronegative atom is reduced, and energy is released
Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration?
glucose → NADH → electron transport chain → oxygen
What process occurs in Box A?
glycolysis
Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?
glycolysis and fermentation
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
oxidation of NADH to NAD+
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
In mitochondrial electron transport, what is the direct role of O2?
to function as the final electron acceptor in the electron transport chain
In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis?
two ATP
In glycolysis, for each molecule of glucose oxidized to pyruvate, ________.
two molecules of ATP are used, and four molecules of ATP are produced
