Enzymatic Reactions/Definition, Inhibitors and Activators

Which of the following is NOT true of enzyme regulation?

• An enzyme can be positively regulated or negatively regulated, depending on cell conditions

• An enzyme can be positively regulated

• An enzyme can be negatively regulated

• Enzyme regulation ensures control on enzyme function

• All enzymes are regulated by the same inhibitors

A non-substrate molecule binds to an enzyme but does not bind at the active site. The enzyme is now unable to bind its substrate. What has likely occurred?

• An activator is bound to the substrate

• The reaction has been catalyzed.

• A competitive inhibitor is bound to the enzyme

• The active site has changed shape

Competitive inhibition involves an inhibitor

• Binding to the active site

• Binding away from the location

• Recognizing a substrate

• Increasing enzyme reaction rates

• Initiating enzyme function

Tags

NGSS.HS-PS1-2

An activator could have the following effect on an enzyme:

• Decrease in enzyme function

• Increase of reaction rates

• Increase in number of substrates that can simultaneously bind to one enzyme

• Increase in inhibitor binding

• Inhibition of substrate binding

Which of the following is NOT true of a noncompetitive inhibitor?

• It is possible for a substrate to still bind to the enzyme

• The enzyme active site can change shape

• The reaction may be completely prevented

• The enzyme may proceed slowly

• The inhibitor can bind in the active site

Tags

NGSS.HS-PS1-2

Click on the temperature that this enzyme is having optimum activity.

Label the diagram.

a

b

c

d

enzyme-substrate complex

substrate

products

enzyme

Enzymes are ​ (a)   that ​ (b)   chemical reactions by​ (c)   the amount of activation energy required to start the reaction.

• proteins
• speed-up
• decreasing
• carbohydrates
• increasing
• slow-down

Tags

NGSS.HS-PS1-5