Flashcards
Enzymes
Cards in this deck (14)
- 1What is an enzyme?Protein molecule (globular protein)= biological catalyst to speed up the rate of a reaction.
- 2What is the lock and key induced fit hypothesis?Enzymes have a specific shape that directly correlates with that of the substrate, meaning= the substrate fits into the active site of the enzyme like a key that specifically fits into a lock.
- 3Induced fit hypothesisThe active site of the enzyme is flexible and can change it's shape slightly to fit the substrate in precisely
- 4The mode of action of enzymesThe process in which an enzyme attracts a substrate to it's active site and catalysis the reaction for a product to form, and then the substrate is released again.
- 5Enzyme - substrate complexThe combination formed between enzyme and substrate.
- 6Activation energyThe energy needed for reactants to be converted into products and to start the reaction (enzymes lower the activation energy).
- 7How does enzyme concentration affect enzyme activity?The greater the concentration, the more frequent collisions between enzyme and substrate, increasing the rate of reaction, provided that there are enough substrate molecules present.
- 8How does substrate concentration affect enzyme activity?The greater the concentration of the substrate, the faster the rate of reactions, provided enough enzyme molecules are present. During enzyme reactions, rates slow down as substrate molecules are used up.
- 9The effect of temperature on enzyme activity.Each enzyme operates at an optimum temperature (work the fastest). Above this, enzyme becomes denatured and ceases to function. (can be permanent)
- 10pH and enzymesEach enzyme has an optimum pH. Some enzymes operate within a narrow pH range and some have a broad pH range.
- 11Competitive inhibitorsMolecules which are similar in shape to the normal substrate molecules. They compete with the substrate for the active site of the enzyme (reversible).
- 12Non-competitive inhibitorsEither bind permanently to the active site or elsewhere on the enzyme causing the active site to change shape (may/ may not be reversible)
- 13efficiency of enzymeCan be measured by finding the Michaelis - Menton constant Km. The maximum rate of reaction Vmax needs to be known and for this the initial rate of reaction should be known at different
- 14Immobilizing enzymesE.g. trapping them in jelly - commercially useful because the enzyme can be re-used and the product is separate/ uncontaminated by the enzyme (can make enzymes more stable)
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- Enzyme mode of action, factors affecting enzyme activity, enzyme inhibitors, enzyme affinities and immobilizing enzymes.
- Created by
- Elric Van Rhyn
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