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Combined Science: Biology

GCSE · Edexcel · higher

QuestionsFlashcards

Disease
Defence Against Disease
Development of Medicines
- Antibiotics
  4
- Discovery & Development of New Drugs
  6
Non-Communicable Diseases
- Lifestyle & Non-Communicable Disease
  8
- Cardiovascular Disease
  6

The Organism in the Environment
Human Influences on the Environment
- Human Impact on Biodiversity
  6
- Benefits of Maintaining Biodiversity
  6
Cycles within Ecosystems

The Action of Enzymes Flashcards

All 5 cards in this deck

What is the active site of an enzyme?: The part of the enzyme that the substrate binds to. Its shape is complementary to the substrate.
Catalase breaks hydrogen peroxide down into water and oxygen. Which of these is the substrate, and which are the products?: Hydrogen peroxide is the substrate; water and oxygen are the products.
What is meant by enzyme specificity?: Each enzyme catalyses only one reaction, because only a substrate with a shape complementary to its active site can fit and bind.
What happens to an enzyme's active site when the enzyme is denatured?: The active site changes shape, so it is no longer complementary to the substrate — the substrate cannot bind and no enzyme-substrate complexes form.
What is the 'lock and key' model of enzyme action?: A model of how enzymes work: the active site has a shape that only the matching substrate fits, just as only the right key fits a lock.