Mekanisme Kerja Enzim : Lock-Key dan Induced Fit

Summary

In this engaging biology lesson, the teacher explains two important theories about enzyme action: the Lock and Key theory, where the enzyme's active site perfectly fits the substrate, and the Induced Fit theory, where the enzyme’s active site is flexible, adjusting to accommodate the substrate. Using simple analogies, the teacher makes complex biological concepts accessible, likening the theories to a lock-and-key relationship or a flexible fit, depending on the enzyme's interaction with the substrate. This explanation helps students understand how enzymes catalyze reactions, offering valuable insights for their studies.

Takeaways

• 😀 Enzymes are proteins that catalyze biochemical reactions, and understanding their mechanism is crucial in biology.
• 😀 The 'lock and key' theory explains enzyme-substrate interaction as a perfect fit, like a key fitting into a lock.
• 😀 In the 'lock and key' theory, the enzyme's active site has a specific shape that precisely matches the substrate.
• 😀 The enzyme-substrate complex forms when the substrate fits into the enzyme's active site, leading to a chemical reaction.
• 😀 The 'induced fit' theory proposes that the enzyme's active site is flexible and adjusts to better fit the substrate.
• 😀 The 'induced fit' theory emphasizes that the enzyme can change its shape to bind with the substrate more effectively.
• 😀 The 'lock and key' theory implies that enzyme-substrate interaction is rigid and does not change once the enzyme-substrate complex forms.
• 😀 The 'induced fit' theory is more flexible and can adapt to slight changes in the substrate shape.
• 😀 The speaker uses analogies, comparing the 'lock and key' theory to a perfect match (like a soulmate) and the 'induced fit' theory to a relationship that requires adjustment (like dating).
• 😀 The main difference between the two theories is that the 'lock and key' theory is more rigid, while the 'induced fit' theory allows for flexibility and adaptation in enzyme function.

Q & A

What are the two main theories explaining how enzymes work?

The two main theories are the 'Lock and Key' theory and the 'Induced Fit' theory.

How does the 'Lock and Key' theory explain enzyme action?

The 'Lock and Key' theory suggests that the enzyme's active site and the substrate fit together perfectly, just like a key fitting into a lock. Once they fit, they form an enzyme-substrate complex, allowing the reaction to occur.

What is another name for the 'Lock and Key' theory?

Another name for the 'Lock and Key' theory is the 'Theory of Specificity' or 'Theory of Complementary Fit'.

What happens if the substrate does not fit into the enzyme's active site in the 'Lock and Key' model?

If the substrate does not fit the enzyme's active site, the reaction will not proceed, as the enzyme cannot bind with the substrate.

What does the 'Induced Fit' theory propose about enzyme function?

The 'Induced Fit' theory suggests that the enzyme's active site is not a perfect fit for the substrate at first. Upon contact, the enzyme changes shape to accommodate the substrate, creating a more suitable fit for the reaction to take place.

Why is the 'Induced Fit' theory also known as the 'Flexible Theory'?

The 'Induced Fit' theory is called the 'Flexible Theory' because it emphasizes the enzyme's ability to adapt its shape to fit the substrate, making it more flexible than the rigid 'Lock and Key' model.

What metaphor is used to explain the 'Induced Fit' theory?

The 'Induced Fit' theory is explained using a metaphor of a person trying to fit into a seat that's slightly too small, and adjusting their position to make a better fit, just like the enzyme adjusting its shape to fit the substrate.

In the 'Lock and Key' theory, what does the enzyme's active site represent?

In the 'Lock and Key' theory, the enzyme's active site represents the lock, and the substrate represents the key. The substrate must fit precisely into the active site for the enzyme to work.

What is the role of the enzyme-substrate complex?

The enzyme-substrate complex is the temporary structure formed when the enzyme and substrate bind together. This complex allows the chemical reaction to proceed.

How does the 'PDKT' analogy help explain the 'Induced Fit' theory?

The 'PDKT' analogy compares the 'Induced Fit' theory to a process of getting to know someone before committing, where the enzyme and substrate may not immediately fit perfectly but adjust to each other, just like people adjusting during the process of getting to know each other.