Exam #2: Assignment 3

Aerobic Respiration Concept Map: Glycolysis yields ________________ and is produced by ______________________

2 ATP; substrate-level phosphorylation

Aerobic Respiration Concept Map: Krebs Cycle yields ________________ and is produced by ______________________

2 ATP; substrate-level phosphorylation

Aerobic Respiration Concept Map: Chemiosmosis yields ________________ and is produced by ______________________

34 ATP; oxidative phosphorylation

Based on the concept map, which of the following is most likely to be true of microbial metabolism? A) The Krebs cycle produces molecules necessary for function of the electron transport chain. B) The energy from 2 ATP is necessary to drive the electron transport chain. C) Acetyl-CoA is converted directly into 2 ATP D) Acetyl-CoA is produced by substrate-level phosphorylation.

A) The Krebs cycle produces molecules necessary for function of the electron transport chain.

One of the most common energy sources used by bacteria is glucose. Why is glucose such a good source of energy for bacteria? A) Glucose is a highly oxidized compound, containing many carbon-hydrogen bonds and a lot of potential energy. B) Glucose is a highly reduced compound, containing many carbon-hydrogen bonds and a lot of potential energy. C) Glucose contains six oxygen atoms, which can be used for oxidative phosphorylation and the generation of many ATP molecules. D) Glucose contains six carbon atoms, which can be quickly incorporated into organic cellular constituents needed for growth.

B) Glucose is a highly reduced compound, containing many carbon-hydrogen bonds and a lot of potential energy.

One of the environmental changes that a bacterium encounters during infection is the limitation of nutrients and oxygen. One of the changes that the bacterium P. multocida (a facultative anaerobe) makes in this environment is to switch to anaerobic metabolism. Predict which of the following is most likely to occur as a result of the switch from aerobic to anaerobic metabolism. A) Glycolysis, the Kreb's cycle, and electron transport will function as usual except that a different compound will be used as a final electron acceptor. B) The organisms will grow more slowly because they will produce less ATP compared to aerobic metabolism. C) During anaerobic metabolism, different electron carriers will be utilized; these will ultimately lead to more ATP production and faster growth of the organism. D) The amount of ATP produced will be relatively the same as aerobic metabolism because P. multocida will be able to respire anaerobically.

B) The organisms will grow more slowly because they will produce less ATP compared to aerobic metabolism.

Based on the concept map, if a new antibiotic is produced that inhibits the synthesis of acetyl-CoA and the electron transport chain in bacteria, for each glucose molecule that could have been metabolized by aerobic respiration, how many fewer ATP molecules will be produced? A) 38 B) 2 C) 4 D) 36 E) 34

D) 36

A key feature of cellular respiration is the removal of electrons from fuel molecules (oxidation) and the ultimate acceptance of these electrons by a low-energy electron acceptor. The process involves the use of electron carriers, NAD+ and FAD, which play crucial roles in multiple steps of the metabolic pathways. The overall equation for cell respiration is shown below. Why do NAD+ and FAD NOT appear in the overall equation? C6H12O6 + 6O2 + 38ADP + 38Pi → 6CO2 + 6H2O + 38ATP A) This pathway doesn't use electron carriers such as NAD+ and FAD and uses only the electron transport chain. B) Glucose and CO2 are the electron carriers in this pathway. C) ADP is the electron carrier in this pathway and picks up electrons to form ATP. D) The NAD+ and FAD are initially reduced then oxidized to their original state, so they do not appear in the net equation.

D) The NAD+ and FAD are initially reduced then oxidized to their original state, so they do not appear in the net equation.

Again, based on the concept map, which of the following processes directly produce the most ATP? A) The Krebs cycle B) Glycolysis C) Synthesis of acetyl-CoA D) The electron transport chain

D) The electron transport chain

Arrange the basic processes of cellular respiration in the correct order. Krebs cycle Electron transport chain Glycolysis

Glycolysis (in cytosol, produces 2 ATP, glucose to pyruvic acid, substrate-level phosphorylation) Krebs cycle (in mitochondria, produces 2 ATP, substrate-level phosphorylation) Electron transport chain (in mitochondria, produces 34 ATP, oxidative phosphorylation)

Aerobic Respiration Concept Map: Order the 5 processes . . . Chemiosmosis Electron transport chain Krebs Cycle Glycolysis Synthesis of Acetyl CoA

In order . . . Glycolysis Synthesis of Acetyl CoA Krebs Cycle Electron transport chain Chemiosmosis