Respiration and Energy: The Powerhouse of Life

 

What is Respiration?

Respiration is the process by which living organisms release energy from food. This energy is used for all the activities that keep them alive, like moving, growing, and staying warm.

Think of it like charging your phone—just as your phone needs energy to work, your body needs energy from respiration to function.

 

Why Do Living Organisms Need Energy?

Here are some ways organisms use energy:

Process	Why It Needs Energy
Muscle Contraction	To move your body (e.g., running or even smiling!).
Protein Synthesis	Building proteins to grow and repair cells.
Cell Division	To make more cells during growth or repair.
Active Transport	Moving substances across cell membranes against the concentration gradient.
Growth	Making new cells and tissues.
Nerve Impulses	Sending messages from the brain to the rest of the body.
Maintaining Body Temperature	Keeping warm in cold environments.

 

The Energy Currency: ATP

The energy released during respiration is stored as ATP (adenosine triphosphate). ATP acts like a rechargeable battery:

1. Energy from food is used to make ATP.
2. ATP releases this energy when needed by cells.
3. Once used, ATP is recharged using more energy from food.

 

Investigating Respiration in Yeast

Yeast is a microorganism that respires to produce energy. We can test how temperature affects respiration in yeast by measuring the amount of carbon dioxide $(CO_2)$ it produces.

Step-by-Step Experiment:

1. Set Up the Equipment:

   • Use a flask with yeast, sugar, and water.
   • Connect it to a test tube filled with limewater.

2. Change the Temperature:

   • Place the flask in a water bath at different temperatures (e.g., $20 \degree C$, $30 \degree C$, $40 \degree C$.

3. Observe the Bubbles:

   • Count the number of bubbles $(CO_2)$ produced per minute
   • The limewater turns cloudy, confirming $CO_2$ production