IGCSE Enzymes

What type of biological molecule is an enzyme?

• Lipid

• Carbohydrate

• Nucleic acid

• Protein

To which part of the enzyme does a substrate molecule bind?

(a)  

Identify the temperature closest to the optimum temperature for a human enzyme

• 20℃

  
  

• 30℃

  
  

• 40℃

  
  

• 50℃

  
  

What term describes an enzyme because it speeds up a chemical reaction?

(a)  

Where do most chemical reactions occur in a cell?

• Cytoplasm

• Ribosomes

• Nucleus

• Mitochondrion

Which organ of the body has enzymes with very low optimun pH

• Pancreas

• Small intestine

• Liver

• Stomach

Which structure in cells has enzymes to catalyse aerobic respiration?

• Nucleus

• Mitochondria

• Ribosomes

• Vacuoles

At temperatures that exceed the optimun an enzyme will become ---------

(a)  

What term best describes the shape of the substrate and active site of an enzyme because they fit together?

(a)  

Identify the optimum pH for an enzyme that catalyses the break down of starch in the mouth

• 2

• 5

• 7

• 9