How Cells Harvest Chemical Energy

Flashcards covering key concepts of cellular respiration, its stages, and metabolic pathways.

What is the overall reaction of cellular respiration?

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)

What are the two main paths of cellular respiration and their ATP yield?

Aerobic path produces net 36 ATP; Anaerobic path produces net 2 ATP.

Define glycolysis.

The multistep chemical breakdown of a molecule of glucose into two molecules of pyruvate.

Where does glycolysis occur?

In the cytoplasm.

What is the product of the citric acid cycle?

6 NADH, 2 FADH2, 2 ATP, and 4 CO2 per glucose molecule.

What is the difference between aerobic respiration and fermentation in terms of ATP yield?

Aerobic respiration produces 36-38 ATP, while fermentation produces a net yield of 2 ATP.

What role does oxygen play in cellular respiration?

Oxygen is used as the final electron acceptor in the electron transport chain.

What are the three main stages of cellular respiration?

Glycolysis, Pyruvate oxidation and the citric acid cycle, and Oxidative phosphorylation.

What is chemiosmosis?

The process of using a concentration gradient to make ATP.

What is the function of ATP synthase?

To synthesize ATP as H+ ions diffuse back into the mitochondrial matrix.

What are NADH and FADH2?

They are reduced coenzymes that carry electrons to the electron transport chain.

What are the two types of fermentation?

Lactic acid fermentation and alcoholic fermentation.

What are the end products of lactic acid fermentation?

Lactic acid and NAD+.

What are the end products of alcoholic fermentation?

Ethanol, CO2, and NAD+.

How do metabolic pathways connect to cellular respiration?

Complex carbohydrates, fats, and proteins can be converted to molecules that enter glycolysis or the Krebs cycle.

What is the role of dehydrogenase in cellular respiration?

Dehydrogenase enzymes remove hydrogen from organic substrates, facilitating redox reactions.

What is the significance of redox reactions in cellular respiration?

They involve the transfer of electrons, releasing energy used to form ATP.

Define substrate-level phosphorylation.

The direct formation of ATP by transferring a phosphate group to ADP in metabolic pathways.

How does fermentation allow glycolysis to continue?

By regenerating NAD+, allowing glycolysis to proceed in the absence of oxygen.

What is the purpose of the electron transport chain?

To transfer electrons and pump H+ ions, creating a gradient for ATP production.