What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
Which of the following statements describes NAD+?
NAD+ is reduced to NADH during both glycolysis and the citric acid cycle.
The oxygen consumed during cellular respiration is involved directly in which process or event?
accepting electrons at the end of the electron transport chain
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is
retained in the pyruvate.
In glycolysis, for each molecule of glucose oxidized to pyruvate
2 molecules of ATP are used and 4 molecules of ATP are produced.
A molecule that is phosphorylated
has an increased chemical reactivity; it is primed to do cellular work.
In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2, 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A. These three steps result in the formation of:
acetyl CoA, NADH, H+, and CO2.
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?
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
Cellular respiration harvests the most chemical energy from which of the following?
During aerobic respiration, electrons travel downhill in which sequence?
food>NADH>electron transport chain>oxygen
During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?
The primary role of oxygen in cellular respiration is to
act as an acceptor for electrons and hydrogen, forming water.
Inside an active mitochondrion, most electrons follow which pathway?
citric acid cycle>NADH>electron transport chain>oxygen
In chemiosmotic phosphorylation, 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
Energy released by the electron transport chain is used to pump H+ ions into which location?
mitochondrial intermembrane space
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is
the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane.
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the
creation of a proton gradient.
Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?
oxidative phosphorylation (chemiosmosis)
Approximately what percentage of the energy of glucose (C6H12O6) is transferred to storage in ATP as a result of the complete oxidation of glucose to CO2 and water in cellular respiration?
In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve?
It increases the surface for oxidative phosphoryation.
The ATP made during fermentation is generated by which of the following?
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of
ATP, CO2, and ethanol (ethyl alcohol).
When muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by
increase in potassium ions.
In vertebrate animals, brown fat tissue's color is due to abundant mitochondria. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few mitochondria. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue?
to regulate temperature by converting energy from NADH oxidation to heat