Enzymes Flashcards
What are catalyst?
A substance that increases the rate of a chemical reaction and is not changed by the reaction.
What are enzymes
Proteins that function as biological catalyst.
catalysts that speeds up the rate of metabolic reaction
Why do enzymes have the lock and key mechanism?
An enzyme works by allowing the molecule of the substance on which it is acting to fit into. The fit has to be perfect.The enzyme is a lock and the molecule fits like a key. They need to be complementary to each other.
Tip: think romance, The enzyme and the substrate fit together and hug. They have soulmates. They complement each other.
What happens to the enzyme when it is at high temperatures?
Above optimum temperatures
It starts to denature
Active site will be distorted as it denatures and it no longer fits the substrate
Whats the temperature where the enzyme works fastest called?
The optimum temperature.
Extra optimum temps:
Digestive enzymes: 37°C
Plant enzymes: 28°C to 30°C
Bacteria enzymes: as high as 75°C
Why is denaturation irreversible?
Once enzymes are denatured they cannot regain their proper shape and activity will stop.
How does pH effect the enzymes?
It affects the shape of the enzyme, most enzymes have a pH of 7 (neutral). If the pH becomes very acidic or very alkaline, the they are denatured. The active site no longer fits the substrate, so the enzyme can no longer catylase its reaction.
Tip: Think romance again but sadder, The toxic friend pH is too much to handle and causes a breakup between two soulmates that always stuck together.
Describe the structure of enzymes?
Enzymes are proteins that contain highly specific active site that fits a specific substrate.
Why are enzymes neccesary in biological systems?
They speed up the reactions so that less energy is needed for the reaction to occur.
Why are enzymes neccesary in biological systems?
They speed up the reactions so that less energy is needed for the reaction to occur.
Describe enzyme action.
A substrate that fits a specific active site of the enzyme binds to create an enzyme-substrate complex, a reaction occurs (catalysed by enzymes) and products are released.
State 4 factors that affect the rate of enzyme controlled reaction.
- Temperature
- pH
- substrate concentration
- enzyme concentration
Why does the rate of reaction increase as temperature increases?
As the temperature increases, the particles have more kinetic energy.
This increases the chance of collisions between molecules being successful and leading to a reaction.
How does a pH that is very to the optimum affect enzyme activity?
The change in pH will distort the active site (denaturing it) so that it can no longer fit the substrate.
