BIO Unit 1 Practice

What is the purpose  of an enzyme?

• give permission for the reaction
• raise activation energy
• speed up reactions
• control how many reactions occur

Where do substrates bind on an enzyme?

• voltage-gated channels
• surface receptor
• calcium channels
• active site

Enzymes are capable of increasing the rate of a chemical reaction within a living cell.  Enzymes accomplish this through which of the following means?

• reducing the number of products   
• reducing the activation energy
• increasing the temperature of the cell
• increasing the concentration of reactants 

What is a substance called if it speeds up a chemical reaction?

• reusable
• catalyst
• specific
• fragile

Each enzyme only has 1 substrate that will fit its active site.  What is this called?

• reusable
• catalyst
• specific
• fragile

The graph shows how enzymes affect reactions in cells. Which statement best summarizes the information shown in the graph?

• Enzymes increase the energy of the reactants.
• Enzymes decrease the energy level of the products.
• Enzyme decrease the activation energy of the reaction.
• Enzymes reverse the direction of the reaction.

Which of the following conclusions can be drawn from this graph?

• The optimum pH of the enzyme is 6.6.
  
• The optimum pH of the enzyme is 5.8
  
• The enzyme’s activity increases as pH increases 5.0 to 9.0
  
• The enzyme’s activity is greater around pH of 8.0 .
  

Enzymes will make a reaction go _______ and use ______ energy.

• faster, less
• faster, more
• slower, less
• slower, more

Which of the following tasks listed below is most associated with enzymes?

• catalyze chemical reactions                  
• store genetic information       
• store chemical energy in the cell   
• dissolve nutrients and minerals 

Cells can produce over one thousand different enzymes at a time.  Enzymes are critical to the metabolism of these cells, but why are so many different enzymes needed?

• Cells are completely unable to control what enzymes
  they produce
• The variety of enzymes prevents their actions from being inhibited. 
• The active site of an enzyme can only bind to a specific substrate.
• The products of a reaction are always converted into new enzymes.