Biology 1.2 Respiration

What is respiration?

A process that releases energy (in the form of ATP) from the breakdown of organic compounds (e.g., glucose).

What is ATP? (Higher)

Short-term energy store in all cells. Universal energy carrier.

What does ATP stand for? (Higher)

Adenosine triphosphate.

Why must respiration occur continuously in living cells?

Energy is required for many essential processes in living cells, e.g., movement, homeostasis, and active transport.

What is aerobic respiration?

A series of enzyme-controlled reactions that form ATP from the breakdown of glucose in the presence of oxygen.

Write the word equation for aerobic respiration.

Glucose + Oxygen → Carbon dioxide + Water + Energy.

What does aerobic respiration require?

Glucose (or another respiratory substance, e.g., lipids, proteins). Oxygen.

What does aerobic respiration produce?

Carbon dioxide. Water. Energy (ATP).

What is anaerobic respiration?

Respiration that takes place without oxygen and forms ATP from the breakdown of glucose.

When may anaerobic respiration take place in muscle cells?

During vigorous exercise.

Write the word equation for anaerobic respiration in muscle cells.

Glucose → Lactic acid + Energy.

Why may anaerobic respiration in muscle cells eventually stop?

Lactic acid build-up inhibits anaerobic respiration.

What are the symptoms of lactic acid build-up?

Cramp and fatigue.

What is oxygen debt?

The extra volume of oxygen that must be taken in after anaerobic respiration to break down lactic acid.

Is aerobic or anaerobic respiration more efficient? Explain why (Higher).

Aerobic respiration is more efficient as it produces more molecules of ATP than anaerobic respiration.

Why does anaerobic respiration release less energy than aerobic respiration? (Higher).

Glucose is only partially broken down in anaerobic respiration./