9-10 Quiz
Glycolysis results in the net production of which of the following sets of molecules per glucose molecule?
2 NADH 2 Pyruvate 2 ATP
Which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?
3 ATP, 6 CO2, 9 NADH, and 3 FADH2
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 net production of which of the following sets of molecules?
ATP, CO2, and ethanol
Which of the following events is most immediately associated with the absorption of energy by chlorophyll molecules of the reaction-center complex?
An electron is excited.
Which of the following molecules is the lowest-energy donor of electrons to the electron transport chain?
FADH2
Which of the following sequences describes the path by which electrons move from high-energy to lower-energy molecules in aerobic respiration?
Glucose --> NADH --> Electron transport chain --> oxygen
Which of the following sequences correctly represents the flow of electrons in photosynthesis?
H2O →→ NADPH →→ Calvin cycle
Which of the following statements best describes the electron transport chain?
It consists of a series of redox reactions. Submit
Which of the following observations would be the best indicator that an photosynthetic organism lacks photosystem II?
It does not produce O2 in the light.
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.
Energy released from the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?
mitochondrial intermembrane space
Assume that it is possible to label each of the molecules below with 18O a heavy isotope of oxygen. As a result of cellular respiration, water containing 18O would most quickly be detected if cells are provided with which one of the following molecules labeled with 18O?
molecular oxygen (O2)
P680+ is said to be the strongest biological oxidizing agent. The strong oxidizing potential of P680+ is essential for its function because it ________.
obtains electrons from the oxygen atom in a water molecule
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
oxidation of NADH to NAD+
Which of the following processes is most directly driven by light energy?
oxidation of chlorophyll molecules
Inhibition of which of the following metabolic pathways would result in a decrease of CO2 production compared to fully functional cellular respiration?
oxidation of pyruvate to acetyl CoA and the citric acid cycle
Which of the following processes is driven by chemiosmosis?
oxidative phosphorylation
The mechanism of photophosphorylation is most similar to which of the following processes?
oxidative phosphorylation in cellular respiration
Which of the following products result from the oxidation of pyruvate to acetyl-CoA?
NADH and CO2
Which of the following molecules is the final electron acceptor for electrons from photosystem I?
NADP+
Which of the following molecules is the primary reducing agent in the Calvin cycle reactions?
NADPH
If pyruvate oxidation is blocked, what is the most likely effect on the levels of oxaloacetate and citrate in the citric acid cycle shown in the accompanying figure?
Oxaloacetate will accumulate and citrate will decrease.
Which of the following statements best describes the relationship between photosynthesis and cellular respiration?
Photosynthesis stores energy in complex organic molecules; cellular respiration releases energy from complex organic molecules. Submit
High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location than the active site. This is an example of which of the following?
allosteric regulation
A greenhouse becomes excessively hot from too much sunlight. One solution is to shade the plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength of light. Which of the following colors would reduce the overall light energy without reducing plant growth?
blue
Which of the following statements best describes the conditions under which the Calvin cycle and cellular respiration occur in plants?
both occur in light or dark
Inhibition of which of the following processes would reduce or eliminate generation of a proton-motive force in mitochondria?
pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space
In the following reaction which molecule functions as the oxidizing agent?Pyruvate + NADH + H+ →→ Lactate + NAD+
pyruvate
Which of the following processes is directly associated with photosystem I?
receiving electrons from the thylakoid membrane electron transport chain
Which of the following processes occurs in the Calvin cycle?
reduction of CO2
Which of the following processes is driven by the free energy released as electrons move through photosystem II and I in the thylakoid membranes?
establishment of a proton gradient Submit
In chemiosmosis, the most direct source of energy used to convert ADP + Pi to ATP is energy released ________.
from movement of protons through ATP synthase, down their electrochemical gradient
Yeast cells with defective mitochondria that are incapable of performing cellular respiration will be able to survive by using which of the following molecules for energy?
glucose
Which of the following metabolic processes normally occurs in yeast cells regardless of oxygen (O2) availability?
glycolysis
Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?
glycolysis and fermentation
If the proteins of the electron transport chain were labeled with a fluorescent tag, the fluorescence observed by microscopy will be localized to which of the following regions of the mitochondria?
inner membrane
The oxygen released by photosynthesis is produced by which of the following processes?
splitting of water molecules
Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?
synthesis of ATP
When a cell is deprived of oxygen, which of the following processes will be inhibited first?
the electron transport chain
Which of the following events takes place in the electron transport chain?
the harnessing of energy from redox reactions to generate a proton gradient
In a plant, which of the following reactions produces molecular oxygen (O2)?
the light reactions alone
In chloroplasts, the photosynthetic electron transport chain acidifies which of the following cellular compartments?
thylakoid space
Substrate-level phosphorylation accounts for approximately what percent of the ATP formed by the reactions of glycolysis?
100%
A mutation that disrupts cyclic electron flow in the light reactions of photosynthesis will reduce the ability to produce which of the following molecules?
ATP
What are the products of linear electron flow in the light reactions of photosynthesis?
ATP and NADPH
Which of the following molecules will accumulate if light reactions occur normally, but the Calvin Cycle is inhibited?
ATP and NADPH
The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis and is inhibited by high levels of which of the following molecules?
ATP and citrate
Depletion of which of the following molecules from the mitochondria will most directly inhibit the citric acid cycle?
NAD+
Which of the following events are associated with chemiosmosis in chloroplasts?
The pH of the stroma increases and ATP is synthesized.
Which of the following describes the function of the pigment molecules in a light-harvesting complex in the thylakoid membranes?
They absorb and transfer light energy to the reaction-center chlorophyll.
Which of the following statements best describes the relationship between the wavelength of light and the quantity of energy per photon?
They are inversely related.
Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. Which of the following statements best describes a related function they serve in plants?
They protect against oxidative damage from excessive light energy.
Which of the following statements describes a primary benefit of having photosystem reaction centers composed of several structurally different pigments?
This arrangement enables the plant to absorb light energy of a variety of wavelengths.
On a spaceship designed to support a multiyear voyage to the outer planets of the solar system, plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be so far from the sun, an artificial light source will be needed to support photosynthesis. Which of the following wavelengths of light should be used to maximize plant growth?
a mixture of blue and red light
Which of the following is one of the molecules formed by the removal of a carboxyl group (as CO2) from a molecule of pyruvate?
acetyl CoA
Which of the following types of metabolic poison would most directly interfere with glycolysis?
agent that closely mimics the structure of glucose but is not metabolized
