Chapter 8: Enzymes Flashcards
Catalyst
A substance that increase speeed up the rate of a chemical reaction and is not a changed by the reaction
Metabolic reactions
Metabolic reactions are all chemical reactions that occur in cells .they include reactions that are catalysed by enzymes
Anabolic reactions
Is a reaction that build complex compounds from simple ones for example photosynthesis
Catabolic reaction
Is a reaction that break down complex compounds into simple ones example digestion of food
Flashcard 1: Enzymes
- Definition: Enzymes are biological catalysts that speed up chemical reactions in living organisms.
- Nature: Enzymes are proteins.
- Specificity: Each enzyme catalyzes a specific reaction.
Flashcard 2: Catalyst
- Definition: A substance that speeds up the rate of a chemical reaction without being consumed in the reaction.
- Enzymes act as catalysts in biological systems.
Flashcard 3: Substrate
- Definition: The specific reactant that an enzyme acts on.
- Enzymes bind to their substrates at the active site to catalyze the reaction.
Flashcard 4: Active Site
- Definition: The region of an enzyme where the substrate binds and the chemical reaction takes place.
- Specificity: The active site has a specific shape that fits the substrate.
Flashcard 5: Enzyme-Substrate Complex
- Definition: The temporary complex formed when an enzyme binds to its substrate.
- The enzyme converts the substrate into the product(s) of the reaction.
Flashcard 6: Lock and Key Model
- Definition: A model for enzyme-substrate interaction where the active site of the enzyme has a specific shape that fits the substrate like a key fits a lock.
Flashcard 7: Induced Fit Model
- Definition: A model for enzyme-substrate interaction where the active site of the enzyme changes shape slightly to accommodate the substrate.
Flashcard 8: Factors Affecting Enzyme Activity
- Temperature
- pH
- Substrate Concentration
- Enzyme Concentration
- Presence of Inhibitors
Flashcard 9: Optimum Conditions for Enzyme Activity
- Temperature: Each enzyme has an optimal temperature at which it works best.
- pH: Each enzyme has an optimal pH at which it works best.
Flashcard 10: Denaturation
- Definition: The change in the shape of an enzyme due to extreme conditions, such as high temperature or extreme pH.
- Denatured enzymes lose their activity because their active site changes shape.
Flashcard 11: Enzyme Inhibitors
- Definition: Molecules that bind to enzymes and decrease their activity.
- Types: Competitive inhibitors and non-competitive inhibitors.
Flashcard 12: Competitive Inhibitors
- Definition: Inhibitors that bind to the active site of an enzyme, competing with the substrate.
- Effect: They reduce the activity of the enzyme by preventing the substrate from binding.
Flashcard 13: Non-Competitive Inhibitors
- Definition: Inhibitors that bind to an allosteric site on the enzyme, not competing with the substrate.
- Effect: They change the shape of the enzyme, reducing its activity.
Flashcard 14: Enzyme-Substrate Concentration Graph
- Shape: Initially, the rate of reaction increases with substrate concentration until all enzymes are occupied (saturation point).
Flashcard 15: Enzyme Denaturation Graph
- Shape: Shows a decrease in enzyme activity with increasing temperature, peaking at the optimum temperature, and then decreasing rapidly due to denaturation.
Flashcard 23:
What is an enzyme
- Term: Enzyme
- Definition:A biological catalyst that speeds up chemical reactions in living organisms.
- Term:Metabolic reactions
- Definition:Chemical reactions that occur within cells of an organism to maintain life. These reactions are responsible for energy production, synthesis of molecules, and breaking down of molecules.
- Term:Characteristics of enzymes
- Details:
- Specificity: Each enzyme works on a specific substrate.
- Efficiency: Speed up reactions without being used up.
- pH and temperature sensitivity: Work best within a specific pH and temperature range.
- Denaturation: Lose their shape and function when exposed to extreme conditions.
- Term: Substrate
- Definition: The molecule or substance the enzyme acts on.
Term:** Active site
- Definition: The ‘dent’ on the enzyme which is exactly the correct shape for the substrate to fit into.
- Term: Enzyme-substrate complex
- Definition: The substrate bonds with the enzyme’s active site and an enzyme-substrate complex is formed.
- Term: Products
- Definition: ‘New’ molecules that leave the active site after the enzyme acts on the substrate.
- Term: Amylase
- Substrate: Starch
- Product: Maltose
- Term: Maltase
- Substrate: Maltose
- Product: Glucose
- Term: Lipase
- Substrate: Lipids (fats & oils)
- Product: Fatty acids & glycerol
- Term: Sucrase
- Substrate: Sucrose
- Product: Fructose & glucose
- Term: Pepsin
- Substrate: Proteins
- Product: Polypeptides
- Term: Trypsin
- Substrate: Polypeptides
- Product: Amino acids
- Term: Optimum temperature
- Definition: The temperature at which the rate of reaction is greatest for an enzyme.
- ## Term: Low temperature effect on enzyme activity
Details: Rate of enzyme activity is slow, less kinetic energy, fewer collisions between enzymes and substrates, fewer ESCs formed.
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Term: High temperature effect on enzyme activity
Details: More kinetic energy, enzyme vibrates too much, breaks bonds, active site changes shape, substrate won’t fit, enzyme denatures.
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*Term:** Optimum pH
- *
*Definition:** The pH where the rate of enzyme activity is the fastest.
- *
*Term:** Amylase activity pH
Details:** Works best in neutral conditions like pH 7-7.5, as in saliva.
- Term:** Pepsin activity pH
Details:** Works best in acidic conditions like in the stomach.
- Term: Lipase activity pH
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Details:** Works best in alkaline conditions like in the duodenum.
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Term:** Seed germination and enzymes
- Details: Seeds contain inactive enzymes and insoluble nutrients. Enzymes become activated when the seed absorbs water. Enzyme amylase changes starch into maltose, protease digests proteins, and lipase digests lipids.
- Term: Biological washing powders and enzymes
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Details:** Contain enzymes which breakdown insoluble proteins, fats, and starch stains. Resulting smaller molecules are soluble and can be washed away easily.
Term: Enzymes in the food industry
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Details:** Rennin or chymosin in cheese making, pectinase in fruit juice production, amylase in bread baking, trypsin in baby food, and papain in tenderizing meat.
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- Term: Biological powder investigation requirements
- Details: Two boiled eggs, two teaspoons, two glass beakers with water, regular and biological detergent.
- Term:Biological washing powder test procedure
- Details:Boil eggs, mark spoons, collect yolk on spoons, dissolve washing powders, observe yolk digestion.
