Enzymes

• What are enzymes primarily known for in chemical reactions?


  Enzymes are biological catalysts that speed up chemical reactions.
• Why do living things produce enzymes?


  To control chemical reactions and obtain the right amounts of substances.
• What happens to reaction rates when temperature is raised?


  Reaction rates usually increase, but unwanted reactions may also speed up.
• What is the consequence of raising the temperature too high in living organisms?


  Cells may start getting damaged.
• What is a catalyst?


  A catalyst is a substance that increases the speed of a reaction without being changed or used up.
• What are enzymes made of?


  Enzymes are large proteins made up of chains of amino acids.
• Why do enzymes have unique shapes?


  Unique shapes are necessary for enzymes to perform their specific functions.
• What is the active site of an enzyme?


  The active site is the part of the enzyme that fits onto the substrate involved in a reaction.
• Why are enzymes considered picky?


  Because they usually only catalyse one specific reaction.
• What happens if the substrate does not match the enzyme's active site?


  The reaction will not be catalysed.
• What is the 'lock and key' model of enzyme action?


  It describes how the substrate fits into the enzyme's active site like a key fits into a lock.
• What is the 'induced fit' model of enzyme action?


  The active site changes shape slightly as the substrate binds to achieve a tighter fit.
• How do enzymes speed up chemical reactions?


  By providing an alternative pathway with a lower activation energy.
• What effect does temperature have on enzyme-catalysed reactions?


  Higher temperatures initially increase the reaction rate, but excessive heat can denature the enzyme.
• What does it mean when an enzyme is said to be denatured?


  It means the shape of the enzyme's active site has changed, preventing substrate binding.
• What is the optimum temperature for most human enzymes?


  Around normal body temperature.
• How does pH affect enzyme activity?


  Extreme pH levels can interfere with the bonds holding the enzyme together, leading to denaturation.
• What is the optimum pH for most enzymes?


  Often neutral pH 7, but can vary for specific enzymes.
• What is the optimum pH for pepsin, an enzyme in the stomach?


  pH 2, which is suited to the acidic conditions in the stomach.
• How do stomach enzymes differ from enzymes in the small intestine regarding pH?


  Stomach enzymes work best at low pH, while small intestine enzymes prefer a higher pH.
• What is the relationship between enzyme activity and temperature?


  Enzyme activity increases with temperature up to a certain point, after which it decreases.
• Why do enzymes require specific conditions to work properly?


  Because they need the right temperature and pH to maintain their shape and function.