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Ch. 3 The Molecules of Cells
Taylor - Campbell Biology: Concepts & Connections 10th Edition
Taylor, Simon, Dickey, Hogan10th EditionCampbell Biology: Concepts & ConnectionsISBN: 9780136538783Not the one you use?Change textbook
All textbooksTaylor, Simon, Dickey, Hogan 10th EditionCh. 3 The Molecules of CellsProblem 18a
Chapter 3, Problem 18a

Enzymes usually function best at an optimal pH and temperature. The following graph shows the effectiveness of two enzymes at various temperatures.
At which temperature does enzyme A perform best?
At which temperature does Enzyme B?
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1
Examine the graph provided. The x-axis represents temperature in degrees Celsius (°C), and the y-axis represents the rate of reaction. The curves for Enzyme A and Enzyme B show how their activity changes with temperature.
Identify the peak of each curve, as this represents the temperature at which each enzyme performs best (optimal temperature). The peak is the highest point on the curve for each enzyme.
For Enzyme A (red curve), locate the temperature at which the curve reaches its maximum height. This is the optimal temperature for Enzyme A.
For Enzyme B (blue curve), locate the temperature at which the curve reaches its maximum height. This is the optimal temperature for Enzyme B.
Conclude that the optimal temperature for each enzyme corresponds to the temperature at the peak of its respective curve, as this is where the rate of reaction is highest.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Enzyme Activity

Enzyme activity refers to the rate at which an enzyme catalyzes a reaction. This activity is influenced by various factors, including substrate concentration, pH, and temperature. Each enzyme has an optimal temperature and pH at which it functions most effectively, beyond which its activity may decrease due to denaturation or altered active site conformation.
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Optimal Temperature

The optimal temperature is the specific temperature at which an enzyme exhibits maximum activity. At this temperature, the kinetic energy of the enzyme and substrate molecules is ideal for facilitating the reaction. Deviations from this temperature can lead to reduced enzyme efficiency and, in extreme cases, denaturation, where the enzyme loses its functional shape.
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Graph Interpretation

Graph interpretation involves analyzing visual data representations to extract meaningful information. In the context of enzyme activity, a graph plotting enzyme effectiveness against temperature allows for the identification of trends, such as peaks indicating optimal performance. Understanding how to read such graphs is crucial for determining the best conditions for enzyme function.
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Textbook Question

Enzymes usually function best at an optimal pH and temperature. The following graph shows the effectiveness of two enzymes at various temperatures.

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