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Enzymes - Coggle Diagram
Enzymes
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In the induced fit model of enzyme action.
The substrate causes the active site to change shape slightly.
The enzyme and substrate from a temporary enzyme – substrate complex.
The substrate is altered.
The enzyme remains unchanged, and the active site returns to its original shape.
Most enzymes
Are specific to a single substrate, owing to the matching shapes of the substrate and active site.
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Enzymes (and other protein) are denatured (lose their shape and activity) by high temperatures (and by unsuitable pH and radiation).
ADP (Adenosine diphosphate) is low energy molecule.
ATP (Adenosine triphosphate) is an energy rich molecule.
ATP is the source of energy used for most cell reactions.
ADP and ATP are interconvertible, i.e., ADP + energy + P ⟶ ATP + water. ATP + water ⟶ ADP + energy + P.
The effects of heat denaturation on catalase can be investigated by:
Boiling catalase,
Testing if it will then form foam when it reacts with hydrogen peroxide.
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NADP+ is a low energy molecule,
NADPH is a high energy molecule.
Both molecules are involved in photosynthesis.
NADP+ and NADPH are interconvertible, i.e., NADP+ + 2 electrons + H ⟶ NADPH. NADPH ⟶ NADP+ + 2 electrons + H.
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Enzyme work because they have the 3-D shape to fit a particular molecule.
Enzymes
Acts on a substrate
Form products
Are made of protein.
Enzymes control metabolic reactions in plant and animals
Amylase is a catabolic enzyme that breaks starch down to maltose
DNA ligase is an anabolic enzyme that joins sections of DNA together.
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The benefit of immobilised enzymes are
They may be reused
They are easy to separate from the product They often more stable than the natural enzyme
The process is cheaper
Immobilised enzymes are used to
Produce fructose (sweetener) from glucose
Convert penicillin to different forms
Produce sweet-tasting sugars from lactose
To investigate the effect of pH on enzyme (catalase) activity:
Mix blended celery (catalase), hydrogen peroxide, pH buffer and washing-up liquid
Note the volume of foam formed after 2 minutes at different pH values.
To investigate the effect of temperature on the rate of enzyme (catalase) activity:
Mix blended celery (catalase), hydrogen peroxide, pH buffer 9 and washing-up liquid
Note the volume of froth formed after 2 minutes at different temperatures.
Yeast contains the enzyme sucrase, which converts sucrose to glucose.
Sucrase is immobilised by:
Mixing yeast solution with sodium alginate solution
Adding beads of the mixture to calcium chloride solution
Rinsing the hardened beads in a sieve.
The application of an immobilised enzyme is shown by:
Adding sucrose solution to immobilised yeast (containing sucrase) in a separating funnel Testing for the production of glucose.