y3 protein

Question 1

chemical elements that make up protein

Answer 1

carbon, hydrogen, oxygen, nitrogen and sulfur

Question 2

Effect of temperature on rate of enzyme-catalysed reaction

Answer 2

• Enzymes are inactive at low temperatures due to low kinetic energy– frequency of collision low
• As temperature increases, kinetic energy increases, frequency of effective collisions between substrate complexes increases, and increases rate of reaction– more products formed
  Enzyme activity is highest at its optimum temperature as all enzyme active sites are occupied
• when temperature is increased beyond the optimum temperature, the enzyme is denatured and loses its catalytic function as the high temperatures break the bonds that keep the enzyme protein in its specific shape, the active site loses its original shape and is no longer complementary to the substrate– no products can be formed.

Question 3

Effect of pH on rate of enzyme-catalysed reaction

Answer 3

• At optimum pH, enzyme functions most efficiently as it maintains its specific 3D conformation and so the active site is complementary to the substrate. Enzyme binds with the substrate(s) to form the enzyme-substrate complex, substrate is converted to products
  Below and above the optimum pH, enzyme is denatured and loses it catalytic function as the structure of the protein is maintained by various bonds and changes in pH alter the bonding pattern, thereby altering the 3D conformation of the active site of the enzyme, hence, the substrate is no longer complementary to the active site, no enzyme-substrate complexes can be formed – no products can be formed.