1. Cyanide is introduced into a culture of cells and is observed binding to a mitochondrion, as shown in the diagram below.

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Sabina Garrison
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1 1. Cyanide is introduced into a culture of cells and is observed binding to a mitochondrion, as shown in the diagram below. The following observations are made: Cyanide binds to and inhibits an enzyme in the inner mitochondrial membrane. There is a decrease in water production in the inner mitochondrial membrane. Cyanide causes a build-up of NADH in the mitochondrial matrix. Which statement best explains where cyanide causes the initial disruption in an important cellular process? (A) Cyanide prevents the production of carbon dioxide by binding to the enzymes involved in the citric acid cycle. (B) Cyanide prevents enzymes from splitting glucose into smaller organic molecules during substrate-level phosphorylation. (C) Cyanide prevents enzymes in the inner membrane from allowing ions to move from areas of lower ph to areas of higher ph. (D) Cyanide prevents the oxidation of energy-rich molecules by binding to enzymes that facilitate movement of the electrons in the electron transport chain. Page 1 of 5

2 2. The diagram below shows the pathway for the movement of electrons in a mitochondrion. Which of the following describes the process in chloroplasts that is most similar to the process shown in the diagram? (A) the reduction of carbon dioxide into 3-carbon sugars in the stroma during the Calvin cycle (B) the excitation of electrons in photosystem II on the thylakoid membrane during the lightdependent reaction (C) the movement of hydrogen ions from a high concentration inside of the thylakoid space to the stroma via chemiosmosis (D) the oxidation of proteins on the thylakoid membrane during noncyclic photophosphorylation to create an electrochemical gradient Page 2 of 5

3 3. A root cutting is placed in a sealed container. The relative levels of carbon dioxide and oxygen gas in the container are measured and recorded in millimeters of mercury (mmhg) every 6 hours over the next 24 hours. The results are shown in the table below. Which statement best explains the results shown in the table? (A) The root cutting is undergoing anaerobic fermentation to generate energy because the low oxygen levels prevent the root cutting from utilizing the citric acid cycle or oxidative phosphorylation. (B) The root cutting is using the Calvin cycle to generate energy by consuming oxygen because there is not enough light available to stimulate the movement of electrons to carry out the light reactions. (C) The root cutting is undergoing aerobic cellular respiration because the root cutting is generating carbon dioxide from organic molecules and is reducing oxygen to form water. (D) The root cutting is undergoing photolysis in the light-dependent reactions because oxygen is being split and combined with carbon to form carbon dioxide. Page 3 of 5

4 4. The diagram below shows how the nutrients triglycerides, glucose, and amino acids are metabolized to generate ATP in a mitochondrion. Which statement best explains how the mitochondrion utilizes nutrients to generate ATP? (A) Triglycerides are utilized to generate ATP only when the amount of FAD is greater than the amount of NAD +. (B) Excess fatty acids in the cytosol are used in the Krebs cycle only when supplies of glucose and amino acids are too low to produce sufficient amounts of Acetyl-CoA. (C) Each type of nutrient is processed by a different pathway in the Krebs cycle, and the number of electrons that can be used to generate ATP is controlled by each pathway. (D) Glucose is utilized to generate ATP through substrate-level phosphorylation when oxygen levels are too low to utilize triglycerides or amino acids via oxidative phosphorylation. Page 4 of 5

5. The diagram below shows the processes occurring in and around the inner mitochondrial membrane. Based on the diagram, which question best investigates a factor that affects the processes shown?

5 5. The diagram below shows the processes occurring in and around the inner mitochondrial membrane. Based on the diagram, which question best investigates a factor that affects the processes shown? (A) What effect will lowering the ph in the intermembrane space have on the proteins in the inner mitochondrial membrane? (B) If oxygen gas is being converted into water in the mitochondrial matrix, will the contents of the mitochondrial matrix become more polar as the processes occur? (C) If water is generated in the mitochondrial matrix, will the mitochondrial matrix become hypotonic to the intermembrane space as the processes occur? (D) What effect will the movement of negatively charged ions through the inner mitochondrial membrane have on the production of water? Page 5 of 5

1. Cyanide is introduced into a culture of cells and is observed binding to a mitochondrion, as shown in the diagram below.

1. Cyanide is introduced into a culture of cells and is observed binding to a mitochondrion, as shown in the diagram below. The following observations are made: Cyanide binds to and inhibits an enzyme