Enzyme Action Flashcards
What do enzymes do?
Enzymes speed up chemical reactions by acting as biological catalysts
What do enzymes lower?
The activation energy of a reaction, often making reactions happen at a lower temperature, which speeds up rate of reaction
What is activation energy?
The minimum amount of energy required for a reaction to start
What is formed when a substrate fits into an enzymes active site?
Enzyme-substrate complex
Give two reasons how enzymes lower the activation energy
- If two substrates need to be joined, being attached to an enzyme holds them close together, reducing any repulsion so they can bond easier
- If the enzyme is catalysing a breakdown, fitting into the enzyme puts strain on the bonds in the substrate making it break up easier
Explain the lock and key model of enzyme action
Where the substrate fits into the enzyme in the same way a key fits into a lock
Explain the induced fit theory of enzyme action
The substrate has to be the right shape to fit into the active site, but also has to make the active site change shape the right way as well
Enzymes are very specific, explain
They are specific, they usually one catalyse one reaction, because only one complimentary substrate will fit into the active site. Each different enzyme has a different tertiary structure and so a different shaped active site. If the substrate shape doesn’t match the active site, an E-S complex won’t be formed and the reaction won’t be catalysed
What happens if the tertiary structure of the enzyme is altered in any way?
The shape of the active site will change, the substrate won’t fit into the active site, an E-S complex won’t be formed and the enzyme will no longer be able to carry out its function
