Factors Affecting Enzyme Activity

Questions and Answers

How does temperature affect enzyme activity?

The rise in temperature makes the enzyme's molecules vibrate more, increasing the rate of reaction. If the temperature goes above a certain level, it can denature the enzyme by changing the shape of the active site.

What is the temperature coefficient, Q10?

Q10 shows how much the rate of reaction changes when the temperature is raised by 10 degrees Celsius. A value of 2 means the rate doubles, while a value of 3 means it trebles. Most reactions have a Q10 value of 2.

How does pH affect enzyme activity?

All enzymes have an optimum pH value. If the pH is above or below this value, it can disrupt the ionic and hydrogen bonds that maintain the enzyme's structure, leading to denaturation.

How does enzyme concentration affect the rate of reaction?

<p>The more enzyme molecules there are, the more likely a substrate molecule is to collide and form an enzyme-substrate complex, increasing the rate of reaction. However, if substrate is limited, excess enzyme will have no effect.</p> Signup and view all the answers

How does substrate concentration affect the rate of reaction?

<p>Higher substrate concentration increases the reaction rate up to a saturation point. After this point, additional substrate does not affect the rate because all active sites of the enzymes are occupied.</p> Signup and view all the answers

Study Notes

Temperature and Enzyme Activity

Increased temperature leads to greater molecular vibration, enhancing reaction rates.
Excessive temperature may break bonds maintaining enzyme structure, changing the active site's shape.
When the active site is altered, enzymes become denatured and lose functionality.

Temperature Coefficient (Q10)

Q10 quantifies the rate change of a reaction when temperature increases by 10°C.
A Q10 of 2 indicates the reaction rate doubles with a 10°C rise, whereas a Q10 of 3 indicates a tripling effect.
Most enzymatic reactions typically exhibit a Q10 value of 2 before reaching optimum temperature.

pH and Enzyme Activity

Each enzyme has a specific optimum pH range for optimal activity.
Deviations in pH can disrupt ionic and hydrogen bonds, destabilizing the enzyme's tertiary structure.
Alterations in active site shape due to pH changes lead to enzyme denaturation.

Enzyme Concentration and Reaction Rate

Higher enzyme concentrations elevate the likelihood of substrate-enzyme collisions, increasing the rate of reaction.
A saturation point occurs when substrate availability limits reaction rate, rendering excess enzyme ineffectual.

Substrate Concentration and Reaction Rate

Reaction rates accelerate with increased substrate concentration up to a saturation threshold.
Beyond saturation, all active sites on enzymes become occupied, negating the effect of additional substrate.
During a reaction, substrate concentration declines, subsequently reducing the reaction rate over time if no further substrate is introduced.

Description

Explore how various factors, including temperature, influence enzyme activity in this informative flashcard quiz. Understand the concept of denaturation and the vital role enzymes play in biological reactions. Perfect for students studying biology or biochemistry.