7.4 Study Guide Flashcards
State the stages of cellular respiration in order.
1st: Glycolysis
2nd: The Link Reaction (or Pyruvate Oxidization)
3rd: The Krebs Cycle (or The Citric Acid Cycle)
4th: The Electron Transport Chain
Which stage(s) of cellular respiration requires glucose as an input? Which stage(s) requires oxygen?
The only stage of cellular respiration that requires an input of glucose is Glycolysis. The Link Reaction, the Krebs Cycle, and the ETC require an input of oxygen.
Which stage(s) of cellular respiration produces an output of carbon dioxide? Approximately how many molecules of ATP are produced per molecule of glucose during cellular respiration?
Both the Link Reaction and the Krebs Cycle produce an output of carbon dioxide. Throughout the entire process of cellular respiration, a total of approximately 34 molecules of ATP is produced for every molecule of glucose.
Which stages of cellular respiration take place within the mitochondria?
The Link Reaction, the Krebs Cycle, and the ETC all take place within the mitochondria. The only stage of cellular respiration that takes place outside the mitochondria is Glycolysis.
What is the overall reaction of cellular respiration?
The overall reaction of cellular respiration can actually be represented by two reactions: C6H12O6 + 6O2 + –> 6CO2 + 6H2O and (~)29ADP + (~)29P –> (~)29ATP + (~)29H2O
What reaction occurs when the human body has no oxygen to perform the link reaction?
When the human body has no oxygen to perform the link reaction, it instead uses its produced pyruvate to perform lactic acid fermentation instead.
Explain how ethanol fermentation and lactic acid fermentation differ. Why are both reactions unsustainable for their performing organisms?
While ethanol fermentation and lactic acid are somewhat similar processes, they differ in several ways. For example, ethanol fermentation is performed by bacteria and yeast while lactic acid fermentation is performed by most animals and fungi, and the former is irreversible while the latter is reversible. Additionally, along with its primary product of ethanol, ethanol fermentation also produces CO2, while lactic acid fermentation only produces lactic acid and ATP. Both reactions are individually unsustainable, as ethanol is toxic at high concentrations and lactic acid fermentation does not produce enough ATP to power the body for long.
What feature of mitochondria greatly increases their rate of energy production? How does it do this?
The rate of energy production of mitochondria is greatly increased by the folds of their inner membranes. A folded membrane in place of an unfolded one allows for the compaction of a much higher amount of membrane and, thus, a much higher amount of ETC and ATP synthase. This allows for the production of high amounts of ATP compared to hypothetical mitochondria with unfolded inner membranes.
