Topic 3 IG/AS - Enzymes

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

• reusable

• catalyst

• specific

• fragile

Answer explanation

A substance that speeds up a chemical reaction is called a catalyst. It increases the rate of the reaction without being consumed in the process.

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

• reusablility

• denaturation

• specificity

• fragility

Answer explanation

Specificity refers to the property of enzymes to have only one substrate that fits their active site, ensuring precise and selective catalysis.

With what 3 letters do enzymes typically end?

• -ose

• -ase

• -ese

• -tic

Answer explanation

Enzymes typically end with the letters -ase. These letters indicate that the substance is an enzyme.

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.

Answer explanation

Enzymes decrease the activation energy of the reaction, facilitating faster reaction rates and increasing efficiency in cells.

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 .
  

Answer explanation

The correct conclusion that can be drawn from the graph is that the optimum pH of the enzyme is 6.6.

Any substance that is acted upon by an enzyme is called a(n)?

• Coenzyme

• Substrate

• Vitamin

• Polypeptide

Answer explanation

A substrate is any substance that is acted upon by an enzyme. In this question, the correct answer is 'Substrate'.

In the diagram, what is letter A? 

• product

• substrate

• enzyme-substrate complex

• active site

Answer explanation

Letter A in the diagram represents the enzyme-substrate complex, which is the correct choice. It is formed when the enzyme binds to the substrate at the active site.

Enzymes are...

• nucleic acids

• proteins

• lipids

• carbohydrates

Answer explanation

Enzymes are proteins. They are biological catalysts that speed up chemical reactions in living organisms.

An enzyme speeds up a chemical reaction in the cell but can only be used once.  True or False? 

• true

• false

Answer explanation

False. An enzyme can be used multiple times to speed up chemical reactions in the cell.

What is the function of an enzyme?

• enzymes break themselves into small pieces

• enzymes slow down chemical reactions

• enzymes speed up chemical reactions

• enzymes combine products to form reactants 

Answer explanation

Enzymes speed up chemical reactions by lowering the activation energy.