Enzymes: Structure, Function, and Activation Energy

Which statement best describes an enzyme in biological reactions?

• A lipid that forms cellular membranes

• A nucleic acid that carries genetic code

• A carbohydrate that stores reaction energy

• A protein catalyst that speeds reactions

What feature allows an enzyme to bind only its specific substrate?

• Presence of metal cofactors

• Number of peptide bonds

• Its overall molecular weight

• A precisely shaped active site

In the sucrose-to-products diagram, what happens to the enzyme after the reaction?

• It remains unchanged and reusable

• It is consumed as a product

• It permanently changes shape

• It detaches and degrades quickly

How do enzymes affect activation energy in a reaction?

• They eliminate free energy change

• They raise the activation energy barrier

• They lower the activation energy barrier

• They keep activation energy constant

Which pairing correctly matches example enzyme and substrate shown?

• Protease acts on starch

• Sucrase acts on sucrose

• Lactase acts on maltose

• Amylase acts on lactose

Which factor would have the least effect on the rate at which an enzyme breaks down starch?

•  the pH of the solution in which the reaction is occurring
• the concentrations of starch and enzyme
• the temperature at which the reaction is taking place
•  the wavelength of light illuminating the reaction

A student is investigating how substrate concentration affects the rate of an enzyme-catalyzed reaction.

Which three variables should be kept constant in the setup of the student’s investigation?

• temperature of the reaction

• amount of enzyme

• amount of substrate

• amount of product

• pH of the reaction

Enzymes are ​ (a)   that act as a biological ​ (b)   that speeds up ​ (c)   .

• chemical reactions
• catalysts
• carbohydrates
• race cars
• proteins
• protists
• lipids
• biologists

Enzymes speed up reaction rates by changing...

• Activation Energy
• pH
• Hydrogen Bonds
• Kinetic Energy

Tags

NGSS.HS-PS1-5

Which color line represent a reaction with an enzyme present?

• Blue

• Red

• Both

• Neither

Tags

NGSS.HS-PS1-5