How does pH influence enzyme reactions

Question 1

What is the pH at which the enzyme achieves the highest rate of reaction

Answer 1

• The optimum pH

Question 2

What is the window around this optimal pH which an enzyme causes a chemical reaction called

Answer 2

• The range

Question 3

Do all enzymes have the same optimal pH at which the rate of chemical reactions is at its highest?

Answer 3

• No
• Each enzyme may have a different optimal pH at which the rate of chemical reaction is highest

Question 4

Do all enzymes increase the rate of chemical reaction within the same range of pH

Answer 4

• No
• Enzymes may cause a reaction within a narrow, or wide range, around the optimal pH

Jamie take a look at the chart on the top of page 34 in advanced biology to see the different ph and different ranges around that ph i.e. narrow range and wide range around the optimal pH

Question 5

What happens if the pH beceomes extreme

Answer 5

• If the pH becomes extreme
• The hydrogen bonds break
• The tertiary 3D structure of the enzyme and therefore function changes
• This change can be permanent
• The enzyme becomes (Denatured)

Question 6

How can acidity and alkalinity influence the enzyme

Answer 6

• Hydrogen ions (H⁺) or Hydroxyl ions (OH^-) can influence the charges on the amino acids at the active site
• Hydrogen bonds can be broken
• This influences the Tertiary structure (3D shape) of the enzymes and the shape of the active site.
• If the active site is flooded with hydrogen (H⁺)or hydroxyl ions (OH^-), the substrate may be unable to fit into the active site if it has the same charge.
• The substrate (Key) can therefore no longer fit into the active site (lock)