Enzymes

Definition

Enzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the process. They play a crucial role in various biological functions, including metabolism, digestion, and cellular processes by lowering the activation energy needed for reactions to occur. The specificity of enzymes allows them to facilitate specific reactions, making them vital for life.

5 Must Know Facts For Your Next Test

1. Enzymes are typically proteins, although some RNA molecules can also have catalytic functions and are known as ribozymes.
2. Each enzyme has a specific optimal temperature and pH range at which it functions best, which is critical for maintaining proper biological processes.
3. Enzymes can be influenced by various factors such as temperature, pH, and concentration of substrates or inhibitors, affecting their efficiency and activity.
4. The lock-and-key model describes how enzymes and substrates fit together perfectly, while the induced fit model suggests that enzymes can change shape slightly to accommodate the substrate.
5. Many enzymes require co-factors or co-enzymes, which are non-protein molecules that assist in the catalytic activity of enzymes.

Review Questions

• How do enzymes influence metabolic pathways and why are they considered essential for life?
  • Enzymes influence metabolic pathways by acting as catalysts that speed up chemical reactions necessary for life processes. They lower the activation energy required for reactions to proceed, allowing metabolic pathways to function efficiently and effectively. Without enzymes, many biochemical reactions would occur too slowly to sustain life, making them essential for growth, reproduction, and maintaining homeostasis.
• Discuss the impact of temperature and pH on enzyme activity and how these factors might affect physiological processes.
  • Temperature and pH significantly impact enzyme activity because each enzyme has an optimal range at which it functions best. If the temperature is too high, enzymes can denature, losing their structure and function. Similarly, if the pH is outside of its optimal range, enzyme activity can be reduced or halted altogether. These changes can disrupt physiological processes, leading to issues such as impaired digestion or slowed metabolism.
• Evaluate how inhibitors can affect enzymatic reactions and discuss the implications of this on drug design.
  • Inhibitors can significantly affect enzymatic reactions by binding to an enzyme's active site or another location, thereby decreasing its activity. This interaction can provide insights into drug design since many pharmaceuticals aim to inhibit specific enzymes related to diseases. Understanding how inhibitors function allows researchers to develop targeted drugs that can modulate enzyme activity effectively, providing therapeutic benefits while minimizing side effects.

Related terms

Substrate: The specific reactant that an enzyme acts upon during a biochemical reaction.

Active Site: The region on the enzyme where the substrate binds and the reaction occurs.

Inhibitor: A substance that decreases or prevents the activity of an enzyme, often by binding to the active site or another part of the enzyme.