Exam 9: Cellular Respiration and Fermentation

Substrate-level phosphorylation occurs within a metabolic pathway where sufficient energy is released by a given chemical reaction to drive the synthesis of ATP from ADP and phosphate.In which of the following metabolic pathways is substrate-level phosphorylation exhibited?

C₆H₁₂O₆ (glucose)+ 6 O₂ → 6 CO₂ + 6 H₂O Where is most of the water in this reaction produced?

The constituents of the electron transport chain have similar capabilities,with the exception of ubiquinone (coenzyme Q).What is different about ubiquinone?

The enzyme phosphofructokinase is the major regulatory enzyme of glycolysis.It catalyzes _____.

Which of the following events takes place in the electron transport chain?

Which electron carrier(s)function in the Krebs cycle?

In the energy-yielding phase of glycolysis,energy is extracted in the form of _____.

The energy of electron transport serves to move (translocate)protons to the outer mitochondrial compartment.How does this help the mitochondrion to produce energy?

Glycolysis is active when cellular energy levels are _____;the regulatory enzyme,phosphofructokinase,is _____ by ATP.

Following glycolysis and the Krebs 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 in the form of _____.

If you were to add one of the eight Krebs cycle intermediates to the culture medium of yeast growing in the laboratory,what do you think would happen to their rates of ATP and carbon dioxide production?

Why might adding inorganic phosphate to a reaction mixture where glycolysis is rapidly proceeding help sustain the metabolic pathway?

The electron transport chain _____.

Two ATP molecules are expended in the energy investment phase of glycolysis.Why is this energy needed to begin the process of glucose catabolism?

The glucose molecule has a large quantity of energy in its _____.

Refer to Figure 9.1 in the text.What characteristic of this molecule (ATP)is responsible for its high energy level?

Canine phosphofructokinase (PFK)deficiency afflicts springer spaniels,affecting an estimated 10% of the breed.PFK is the glycolytic enzyme that phosphorylates fructose-1-phosphate and catalyzes the committed step in glycolysis.Given its critical role in glycolysis,one implication of the genetic defect resulting in PFK deficiency in dogs is _____.

Which of the following statements about cellular metabolism is false?

Why are fermentation reactions important for cells?

The chemiosmotic hypothesis is an important concept in our understanding of cellular metabolism in general because _____.