Question

Energy stored in respiration :

• A. In the form of ADP
• B. In the form of ATP
• C. In the form of NADP
• D. In the form of PI

Hint:

Think of {ATP} as the cell's rechargeable battery or energy money.
Respiration (like burning fuel - glucose) "charges the battery" or "earns money" by converting ADP into ATP.
When the cell needs energy for work, it "uses the battery" or "spends the money" by converting ATP back to ADP, releasing energy. So, energy from respiration is stored as ATP.

Answer 1

The Correct Option is B

Concept: Cellular respiration is the metabolic process by which organisms break down glucose and other food molecules to release chemical energy. This released energy is then captured and stored in a readily usable form. Step 1: The Purpose of Cellular Respiration The primary goal of cellular respiration is to convert the chemical energy stored in organic molecules (like glucose) into a form of energy that cells can use to perform various life processes (e.g., muscle contraction, active transport, synthesis of molecules). Step 2: The Energy Currency of the Cell - ATP The molecule that serves as the main "energy currency" of the cell is Adenosine Triphosphate (ATP). During cellular respiration, energy released from the breakdown of glucose is used to synthesize ATP from Adenosine Diphosphate (ADP) and inorganic phosphate (\(P_i\)). \[ ADP + P_i + \text{Energy (from glucose breakdown)} \rightarrow ATP \] When the cell needs energy, ATP is hydrolyzed (broken down) back into ADP and \(P_i\), releasing the stored energy: \[ ATP \rightarrow ADP + P_i + \text{Usable Energy} \] Step 3: Analyzing the options
(1) In the form of ADP (Adenosine Diphosphate): ADP is the lower-energy form to which ATP is converted when energy is used. Energy is {used to convert} ADP to ATP, not stored as ADP itself primarily.
(2) In the form of ATP (Adenosine Triphosphate): Correct. ATP is the molecule in which the energy released during respiration is stored and transported for cellular work.
(3) In the form of NADP (Nicotinamide Adenine Dinucleotide Phosphate): NADP\(^+\)/NADPH is an electron carrier primarily involved in anabolic reactions like photosynthesis (carrying reducing power). While NADH (related to NAD\(^+\)) is an electron carrier in respiration whose energy is eventually used to make ATP, NADP itself is not the primary energy storage molecule from respiration.
(4) In the form of PI (Inorganic Phosphate): \(P_i\) is a component used to make ATP (from ADP + \(P_i\)), but it's not the form in which energy is stored. Therefore, energy released during respiration is stored in the chemical bonds of ATP.