$$\mathrm{C_6H_{12}O_6$} + 6\,O_2$ \rightarrow 6\,CO_2$ + 6\,H_2O + \text{energy (ATP)}$$

Question 1

Which process in the ecosystem diagram converts light energy into chemical energy stored in organic molecules?

Accepted Answer

Photosynthesis in chloroplasts

Question 2

During glycolysis, which molecule is directly responsible for accepting electrons and becoming reduced?

Accepted Answer

NAD+

Question 3

What is the net ATP gain from glycolysis per glucose molecule?

Accepted Answer

$$2$$

Question 4

Which equation best represents the overall process of cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\,O_2$ ightarrow 6\,CO_2$ + 6\,H_2O + 	ext{energy (ATP)}$$

Question 5

In the oxidation of pyruvate, which molecule is produced and enters the citric acid cycle?

Accepted Answer

Acetyl CoA

Question 6

Which step of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 7

What is the primary function of the electron transport chain in mitochondria?

Accepted Answer

To create a proton gradient for ATP synthesis

Question 8

Which enzyme is directly responsible for synthesizing ATP during chemiosmosis?

Accepted Answer

ATP synthase

Question 9

If oxygen is not present after glycolysis, what is the fate of pyruvate in human cells?

Accepted Answer

It is converted to lactate

Question 10

Why must NAD+ be regenerated during fermentation?

Accepted Answer

To allow glycolysis to continue producing ATP

Question 11

Which molecule acts as an allosteric inhibitor of phosphofructokinase in glycolysis?

Accepted Answer

ATP

Question 12

What is the main purpose of the citric acid cycle?

Accepted Answer

To generate NADH and FADH2 for the electron transport chain

Question 13

Which of the following is a product of fermentation in yeast?

Accepted Answer

Ethanol

Question 14

What would happen if the proton gradient across the mitochondrial membrane was disrupted?

Accepted Answer

ATP synthesis would decrease

Question 15

Which equation represents ATP synthesis by ATP synthase?

Accepted Answer

$$\mathrm{ADP} + P_i \rightarrow \mathrm{ATP} + H_2O$$

Question 16

Which metabolic pathway is most affected by a poison that inhibits Complex I of the electron transport chain?

Accepted Answer

Oxidative phosphorylation

Question 17

If a person takes a drug that uncouples oxidative phosphorylation, what is the most likely immediate effect?

Accepted Answer

Decreased ATP production and increased heat generation

Question 18

Which molecule is regenerated during fermentation to allow glycolysis to continue?

Accepted Answer

NAD+

Question 19

What is the main advantage of storing excess energy as fat rather than carbohydrates?

Accepted Answer

Fat stores more energy per gram

Question 20

Which of the following best describes the relationship between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis produces oxygen and glucose, which are used in cellular respiration

Energy and Enzymes: Cellular Respiration, Photosynthesis, and Metabolic Pathways

Study Guide - Practice Questions