CHAPTER 9 BIOLOGY
A typical eukaryotic cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen to an individual when they exhaust their ATP supply?
Catabolic processes will be activated to generate additional ATP.
Which of the following statements best explains why carbohydrates and fats may be considered high-energy foods?
They contain many electrons associated with hydrogen atoms.
The synthesis of ATP by oxidative phosphorylation is an example of which of the following processes?
coupling of an endergonic reaction to an exergonic reaction
Under which conditions will plant cell mitochondria actively oxidize pyruvate and carry out oxidative phosphorylation?
in all cells, with or without light
In chemiosmosis, the most direct source of energy used to convert ADP + i to ATP is energy released ________.
from movement of protons through ATP synthase, down their electrochemical gradient
Which of the following best predicts the effect of removal of oxygen from a facultative anaerobic organism's environment?
glucose consumption increases, while the growth rate decreases
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
glycolysis
Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?
glycolysis and fermentation
In which reactions of cellular respiration does substrate-level phosphorylation occur?
in both glycolysis and the citric acid cycle
ATP synthase at the inner mitochondrial membrane makes ATP and water from ADP and phosphate by coupling this to which other process?
allowing H+ to move down its electrochemical gradient
In liver cells, the inner mitochondrial membranes contain about five times the surface area of the outer mitochondrial membranes, which allows for increased rates of which process below?
oxidative phosphorylation
Which of the following processes is driven by chemiosmosis?
oxidative phosphorylation
the inner mitochondrial membranes contain about five times the surface area of the outer mitochondrial membranes, which allows for increased rates of which process below?
oxidative phosphorylation
When a glucose molecule loses a hydrogen atom in an oxidation-reduction reaction, the glucose molecule is ________.
oxidized
In mitochondria, exergonic redox reactions ________.
provide the energy that establishes the proton gradient
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
When electrons are passed from one atom to a more electronegative atom, the more electronegative atom is ________.
reduced, and energy is released
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 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
If a cell produces on average 30 ATP molecules for each molecule of glucose that is completely oxidized to carbon dioxide and water, how many ATP molecules on average can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?
14
If glucose is the sole energy source for cellular respiration in an animal, what proportion of the carbon dioxide exhaled is derived from oxidation of pyruvate to acetyl CoA?
1/3
Substrate-level phosphorylation accounts for approximately what percent of the ATP formed by the reactions of glycolysis?
100%
Which of the summary statements below best describes the results of the following reaction? C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy
C6H12O6 is oxidized and O2 is reduced.
Which of the following statements best describes the electron transport chain?
It consists of a series of redox reactions.
Which of the following statements best supports the claim that glycolysis is likely 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.
Which of the following statements best describes how a reducing agent in is chemically altered in a biological redox reaction?
It loses a hydrogen atom and loses potential energy.
Depletion of which of the following molecules from the mitochondria will most directly inhibit the citric acid cycle?
NAD+
Which of the following statements best describes a characteristic of NAD+?
NAD+ is reduced to NADH in glycolysis, pyruvate oxidation, and the citric acid cycle.
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
Ph of matrix increases
What types of cells carry out ATP synthesis by chemiosmosis?
all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors
Energy released from the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?
mitochondrial intermembrane space
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
oxidation of NADH to NAD+
Inhibition of which of the following metabolic pathways would result in decreased rates of CO2 production?
oxidation of pyruvate to acetyl CoA The citric acid cycle
What is the purpose of fermentation reactions?
to regenerate NAD+ so glycolysis can continue