Ch.19 Enzymes and Vitamins

McMurry - Fundamentals of General, Organic, and Biological Chemistry 8th Edition

McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187당신이 사용하는 게 아니라요?교과서 변경

McMurry 8th Edition

Ch.19 Enzymes and Vitamins

문제 84

19장, 문제 84

What is the activation energy for a reaction? Why is activation energy necessary?

검증된 단계별 안내

The activation energy (Ea) is the minimum amount of energy required for reactants to collide with enough force to overcome the energy barrier and form products. It is typically measured in units of joules (J) or kilojoules per mole (kJ/mol).

Activation energy is necessary because it ensures that only molecules with sufficient energy can successfully collide and react. This prevents random, low-energy collisions from leading to reactions, which helps maintain the stability of substances under normal conditions.

To calculate the activation energy, you can use the Arrhenius equation:

E_a = -R 	imes \(\text{ln}\)(k_2/k_1) / (1/T_2 - 1/T_1)

, where R is the gas constant (8.314 J/mol·K), k₁ and k₂ are the rate constants at temperatures T₁ and T₂ (in Kelvin), respectively.

If experimental data is provided, such as rate constants (k₁ and k₂) and corresponding temperatures (T₁ and T₂), substitute these values into the Arrhenius equation to solve for Ea. Ensure all units are consistent, particularly for temperature (Kelvin) and the gas constant.

Graphically, activation energy can also be determined by plotting

\(\text{ln}\)(k)

versus

1/T

. The slope of the resulting line is equal to

-E_a/R

, which can be rearranged to calculate Ea.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Activation Energy

Activation energy is the minimum amount of energy required for a chemical reaction to occur. It represents the energy barrier that reactants must overcome to transform into products. This concept is crucial in understanding reaction rates, as higher activation energies typically lead to slower reactions, while lower activation energies facilitate faster reactions.

Reaction Mechanism

A reaction mechanism is a step-by-step description of the pathway taken during a chemical reaction. It outlines the sequence of elementary steps that lead to the formation of products from reactants. Understanding the mechanism helps in identifying the activation energy and the factors that influence it, such as temperature and catalysts.

Catalysts

Catalysts are substances that increase the rate of a chemical reaction by lowering the activation energy without being consumed in the process. They provide an alternative pathway for the reaction, making it easier for reactants to convert into products. The presence of a catalyst is essential in many industrial processes, as it enhances efficiency and reduces energy costs.

관련 실천

교과서 질문

How will changing the conditions in an enzymatic reaction affect the rate of that reaction? Explain why in each case.

f. Decreasing the amount of substrate by half

1014

views

교과서 질문

Why are irreversible enzyme inhibitors referred to as poisons?

1556

views

교과서 질문

How can you distinguish between a competitive inhibitor and an uncompetitive inhibitor experimentally?

1344

views

교과서 질문

Apple slices and peeled potatoes rapidly brown in open air due to the presence of phenolases. Phenolases cause the oxidation of phenolic molecules like tyrosine to quinones, colored molecules responsible for the brown colors seen. An experiment comparing the time it took for a change to occur in the color of apple slices versus potato slices was done to test for phenolase activity. Then, a second experiment was done with new apple and potato slices with H2O2 measuring time until bubbles appeared.

b. Which sample contains more catalase? Why?

528

views

교과서 질문

Look up the structures of vitamin C and vitamin E on the Web, and identify the functional groups in these vitamins.

740

views

교과서 질문

What is the relationship between vitamin A and β-carotene?

1571

views