11 AS Practice: Enzyme action

The diagram represents enzyme action.

What are parts W, X and Y in this chemical reaction?

• W is the enzyme, X is the product, Y is the substrate

• X is the enzyme, W is the product, Y is the substrate

• X is the enzyme, Y is the product, W is the substrate

• Y is the enzyme, W is the product, X is the substrate

Tags

NGSS.HS-PS1-5

The diagram represents the shape of an enzyme molecule.

With which substrate would this enzyme most easily form an enzyme-substrate complex?

• 
• 
• 
• 

The diagrams show molecules involved in the action of a a catabolic enzyme such as maltase.

Which is the substrate?

• 
• 
• 
• 

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-5

Which explains how enzymes can be recycled?

• Enzymes are not used up in a chemical reaction.

• Enzymes increases during a chemical reaction.

• Enzymes change to a different type after a chemical reaction.

• Enzymes reuse substrates in a chemical reaction.

What is left at the end of an enzyme-controlled reaction?

• enzymes and products

• enzymes and substrates

• enzymes only

• products only

Enzymes __________________ the activation energy of a chemical reaction.

• decrease

• increase

• absorb

• release

In the liver glucose molecules form into glycogen. This is an example of anabolism. What is meant by anabolism?

• Building up large molecules from smaller ones.

• Breaking down large molecules from smaller ones.

Lactase is a human enzyme that catalyses the breakdown of lactose in milk.

At which temperature does lactase work fastest?

• 0°C

• 18°C

• 37°C

• 100°C

Tags

NGSS.HS-PS1-5

The graph shows the effect of pH on a particular enzyme-controlled reaction.

When is the enzyme not active?

• at pH 1 and pH 13

• at pH 3 and pH 11

• at pH 5 and pH 9

• at pH 7

Many enzymes do not work at temperatures above 60 °C.

Which statement explains this?

• Product molecules are not made because the active site has changed shape.

• Product molecules change shape so they do not fit the active site.

• Substrate molecules are moving too fast.

• Substrate molecules are moving too slowly.