Ch 4 Enzymes

What are enzymes?

• Carbohydrates that slow down reactions

• Proteins that accelerate reactions

• Lipids that store energy

• Nucleic acids that carry genetic information.

Enzymes can accelerate the rate of a reaction by factors of as much as a ______ or more.

• hundred

• thousand

• million

• billion

Which enzyme has the highest rate enhancement according to the table?

• OMP decarboxylase

• Staphylococcal nuclease

• Carboxypeptidase A

• Carbonic anhydrase

The hydration of CO2 by carbonic anhydrase accelerates the reaction by how many fold? Fill in the blank: The reaction is accelerated by ______ fold.

• 1 million

• 5 million

• 10 million

• 15 million

Which of the following is a reason why enzymes have higher reaction rates compared to most chemical catalysts?

• They work at extreme temperatures

• They are proteins

• They have orders of magnitude better reaction rates

• They cannot be regulated

Enzymes work under milder reaction conditions. They operate at physiological pH and ______.

• high pressure

• low temperature

• high temperature

• physiological temperature

Enzymes have greater reaction specificity. This means they are specific in terms of reactants and ______.

• temperature

• pressure

• products

• pH

Why is the ability to regulate enzymes important for metabolism?

• It allows for constant reaction rates

• It enables metabolism to respond to changing demands

• It prevents any changes in catalysis

• It ensures enzymes work only at high temperatures

Which enzyme catalyzes oxidation-reduction reactions?

• Transferases

• Oxidoreductases

• Hydrolases

• Ligases

_________ cleave bonds with the addition of water.

• Lyases

• Isomerases

• Hydrolases

• Ligases