Pupil sheet · Enzymes
Enzymes — return questions
Name ______________________ Date ____________
Use one to two weeks after the lessons. Keep the notes and the lesson closed.
1. state
Which statement about enzymes is correct?
Circle one answer.
- Enzymes are proteins that act as biological catalysts
- Enzymes are carbohydrates that store energy
- Enzymes are living cells that digest food
- Enzymes are used up in every reaction they speed up
2. complete
Complete the sentences about enzyme action.
The substrate fits into the … of the enzyme
because their shapes are …
Together they form an enzyme–substrate …
The substrate is changed into …
Each enzyme acts only on its own substrate, or a few very similar ones: enzymes are …
3. explain
Explain why enzymes are important in all living organisms.
4. identify
Which statement about temperature and enzymes is correct?
Circle one answer.
- Enzymes work faster the hotter it gets, at every temperature
- Cold temperatures denature enzymes permanently
- Above the optimum the active site changes shape and the enzyme is denatured
- At the optimum the enzyme is used up fastest
5. complete
Complete the sentences about temperature and enzymes.
As the temperature rises, the molecules have more … energy,
so there are more frequent effective …
Above the optimum the active site changes …
and the enzyme is …
6. state
What is the optimum pH of an enzyme?
Circle one answer.
- The pH at which the enzyme is denatured
- The pH at which the enzyme works fastest
- pH 7 for every enzyme
- The pH of the substrate
7. complete
Complete the sentences about pH and enzymes.
Away from its optimum pH, the active site changes …
so the substrate … less well
and fewer enzyme–substrate … form.
At an extreme pH the enzyme is …