Cellular Respiration Quiz

What is the main role of oxygen in cellular respiration?

• To produce glucose

• To act as a final electron acceptor

• To generate carbon dioxide

• To break down ATP

Answer explanation

The main role of oxygen in cellular respiration is to act as a final electron acceptor in the electron transport chain, allowing for the production of ATP and water, which is essential for energy metabolism.

What process involves the transfer of electrons through a series of carriers to produce ATP?

• Glycolysis

• Krebs cycle

• Electron transport chain

• Fermentation

Answer explanation

The electron transport chain is the process where electrons are transferred through a series of carriers, ultimately leading to the production of ATP. This occurs in the inner mitochondrial membrane and is crucial for cellular respiration.

What is chemiosmosis primarily responsible for in cellular respiration?

• Breaking down glucose

• Synthesizing proteins

• Generating ATP

• Producing oxygen

Answer explanation

Chemiosmosis is the process by which ATP is generated in cellular respiration. It occurs in the mitochondria, where the flow of protons across the membrane drives the synthesis of ATP from ADP and inorganic phosphate.

What is the main product of glycolysis?

• Glucose

• ATP

• Pyruvate

• NADH

Answer explanation

The main product of glycolysis is pyruvate, which is formed from glucose through a series of enzymatic reactions. While ATP and NADH are produced during glycolysis, pyruvate is the final product that enters the next metabolic pathways.

What is the role of ATP in glycolysis?

• It is a waste product

• It provides energy

• It is converted into glucose

• It is used to transport oxygen

Answer explanation

In glycolysis, ATP provides the necessary energy to drive the reactions forward. It is consumed in the early steps to phosphorylate glucose, making it more reactive and facilitating its breakdown for energy production.

What happens to pyruvate in the link reaction?

• It is converted into glucose

• It is oxidized to form acetyl CoA

• It is stored as fat

• It is used to produce oxygen

Answer explanation

In the link reaction, pyruvate is oxidized to form acetyl CoA, which is essential for entering the citric acid cycle. This process does not convert pyruvate into glucose, store it as fat, or produce oxygen.

What is the main purpose of the Krebs cycle?

• To produce glucose

• To generate ATP and electron carriers

• To store energy as fat

• To convert oxygen into carbon dioxide

Answer explanation

The main purpose of the Krebs cycle is to generate ATP and electron carriers, which are essential for energy production in cells. It does not produce glucose, store energy as fat, or convert oxygen into carbon dioxide.

What is the primary function of NADH in cellular respiration?

• To store energy as fat

• To act as an electron carrier

• To produce glucose

• To break down ATP

Answer explanation

The primary function of NADH in cellular respiration is to act as an electron carrier. It transports electrons to the electron transport chain, facilitating ATP production through oxidative phosphorylation.

Which process in cellular respiration occurs in the cytoplasm?

• Krebs cycle

• Electron transport chain

• Glycolysis

• Link reaction

Answer explanation

Glycolysis is the only process in cellular respiration that occurs in the cytoplasm. The Krebs cycle and electron transport chain occur in the mitochondria, while the link reaction takes place in the mitochondrial matrix.

What is the role of FADH2 in the electron transport chain?

• To synthesize proteins

• To generate carbon dioxide

• To donate electrons

• To produce oxygen

Answer explanation

FADH2 plays a crucial role in the electron transport chain by donating electrons to the chain, which helps in the production of ATP. This process is essential for cellular respiration and energy production.