5. Enzymes Flashcards
What is the optimum pH for an enzyme?
The pH at which the enzyme works the best.
What is denaturation of an enzyme?
A permanent alteration in the enzyme’s active site.
What are factors that can lead to denaturation of an enzyme?
pH and temperature.
What is the function of the enzyme amylase?
It breaks down starches into sugars (like glucose).
What is the function of the enzyme lipase?
It breaks down fat in the stomach.
What is the function of the enzyme maltase?
It breaks down maltose (sugar) into glucose.
What is the function of the enzyme trypsin?
It breaks down proteins into amino acids.
What is the function of the enzyme lactase?
It breaks down lactose into glucose and galactose.
What is a catalyst?
a substance that increases the rate of a chemical reaction but is unchanged by the reaction
What are enzymes?
proteins involved in all metabolic reactions, functioning as biological catalysts
Why are enzymes important?
provide reaction rate necessary to sustain life
What are some uses of enzymes? (do not need to name all)
- food production
- agriculture
- cosmetic and pharmaceutical industries
- production of biofuels.
- production of cheese, bread, leather, fruit juice and lactose-free milk
- production of certain textiles
- medical diagnostic testing
- digestion, breaking down substances in food
Describe enzyme action.
- each type of enzyme has a specific shape that fits the reactants in the reaction
- shape of active site and substrate are complementary
- substrate fits into active site and reaction happens
- product(s) leave the active site.
- enzyme is ready to act again
Investigate and describe the effect of changes in temperature on enzyme activity.
- low temp: KE of molecules too low for effective collisions to occur, breakdown rate low
- as temp increases, so does KE of the molecules, causing more effective collisions
- temp exceeds optimum temperature of the enzyme, active site shape changes (no longer fits) enzyme begins to denature, slowing the reaction
Investigate and describe the effect of changes in pH on enzyme activity.
- optimum pH at which the shape of the active site allows the enzyme to work most efficiently
- above and below optimum pH, enzyme undergoes denaturation
What is an enzyme-substrate complex?
structure formed when a substrate attaches to the active site of an enzyme
structure formed when a substrate attaches to the active site of an enzyme
enzyme-substrate complex
What is the active site?
region of an enzyme where catalysis happens and fits with substrate
What is the substrate?
reactant in an enzyme-catalysed reaction
Explain enzyme action in more detail.
- enzyme’s active site and substrate fit together to make an enzyme–substrate complex
- reaction happens
- products are produced and detach from enzyme, making it available to catalyse another reaction
Explain the specificity of enzymes.
- each type of enzyme only works for one/very few reactions
- active site has a specific shape that only the correct substrate (or a very similarly shaped molecule) can fit into (complementary)
It breaks down starches into sugars (like glucose).
amylase
It breaks down fat in the stomach.
lipase
It breaks down maltose (sugar) into glucose.
maltase
It breaks down proteins into amino acids.
trypsin
It breaks down lactose into glucose and galactose.
lactase
