BTEC Applied Science Level 3 (Unit 3) Enzymes & Diffusion

Which of the following best explains why enzymes are necessary for reactions in our cells?

• The reactions are too slow to meet the needs of the cell if enzymes are missing.

• Enzymes supply the oxygen necessary for the reactions.

• Enzymes change reactants from solid to liquid during the reactions.

• The reactions take up too much space in the cell if enzymes are missing.

The substance that binds to an enzyme is called a?

• Polypeptide

• Co-enzyme

• Vitamin

• Substrate

What is the optimal pH for this enzyme?

• 6

• 10

• 9

• 7

The ____________________ mechanism describes how each substrate must fit into the enzyme.

• lock and key

• hammer and nail

• jigsaw puzzle

• seesaw

What is the purpose of an enzyme?

• control how many reactions occur

• raise activation energy

• give permission for the reaction

• speed up chemical reactions

The _____________________ mechanism describes how an enzyme changes shape once the substrate is bonded.

• hammer and nail

• induced fit

• jigsaw puzzle

• lock and key

Where do substrates bind to an enzyme?

• calcium channels

• active site

• receptor molecules

• voltage-gated channels

Once a new product leaves an enzyme, the enzyme is unchanged and ready for the next substrate. What is this called?

• fragile

• reusable

• specific

• catalyst

All of the following affect the functioning of an enzyme EXCEPT:

• pH

• temperature

• metabolism

• enzyme concentration, substrate concentration, inhibitor molecules

After the enzyme and substrate bind together and perform the reaction, what does the substrate become?

• a substrate

• an active site

• an enzyme

• a product