Understanding Irritability in Living Organisms

What is Irritability?

Irritability is the ability of living organisms to respond to stimuli in their environment. These stimuli can be changes in temperature, pH, light, and other environmental factors.

Types of Stimuli

• Temperature: Organisms respond to changes in temperature to maintain homeostasis. For example, humans sweat to cool down when it's hot.
• pH: The pH level can affect enzyme activity. Enzymes work best at specific pH levels, and deviations can slow down or stop biological processes.
• Light: Light intensity can influence processes like photosynthesis in plants and circadian rhythms in animals.

Effects of Stimuli on Enzymes

Enzymes are proteins that speed up chemical reactions in the body. Their activity can be affected by:

• Temperature: Enzymes have an optimal temperature range. Too high or too low temperatures can denature enzymes, reducing their effectiveness.
• pH: Each enzyme has an optimal pH. Extreme pH levels can lead to enzyme denaturation.

Examples of Responses to Stimuli

• Temperature: Reptiles bask in the sun to increase their body temperature.
• pH: Fish in acidic waters may experience stress, affecting their survival.
• Light: Plants grow towards light sources, a response known as phototropism.