Mastering Biology : Chapter 7
Metabolic pathways that release stored energy by breaking down complex molecules are known as
catabolic pathways.
The complete oxidation of glucose (C6H12O6) to carbon dioxide and water in aerobic respiration consumes how many molecules of oxygen (O2)?
6
Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?
Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).
In the combined processes of glycolysis and cellular respiration, what is consumed, and what is produced?
Glucose is consumed, and carbon dioxide is produced
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.
H+ concentration gradient across the membrane holding ATP synthase
When electrons flow along the electron transport chains of mitochondria, which of the following changes occur?
The pH of the matrix increases.
Why are carbohydrates and fats considered high-energy foods?
They have a large number of electrons associated with hydrogen.
As a result of an oxidation-reduction reaction the oxidizing agent
gains electrons and gains potential energy.
Which of the following indicates a primary path by which electrons travel downhill energetically during aerobic respiration?
glucose → NADH → electron transport chain → oxygen
The complete oxidation of glucose in aerobic respiration occurs through which of the following sequence of metabolic reactions?
glucose → glycolysis → pyruvate oxidation → citric acid cycle → electron transport chain
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
glycolysis
When an electron is transferred to a more electronegative atom
it loses potential energy.
The complete reactions of cellular respiration in the presence of oxygen (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy) result in which of the following?
oxidation of C6H12O6 and reduction of O2
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the glucose molecule becomes
oxidized.
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is __________.
oxygen
In mitochondria, exergonic redox reactions __________.
provide the energy that establishes the proton gradient
What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ → Lactate + NAD+
pyruvate
Most CO2 from catabolism is released during __________.
the citric acid cycle
As a result of the transfer of an electron from a less electronegative atom to a more electronegative atom,
the more electronegative atom is reduced, and energy is released.
Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration?
transforming the energy in glucose and related molecules in a chemical form that cells can use for work
