Enzymes Flashcards
What are enzymes?
Enzymes are proteins that speed up reaction rates but remain unchanged at the end of the reaction.
What happens to enzymes when exposed to heat?
Enzymes are denatured by heat.
What is the relationship between the quantity of enzymes and chemical reactions?
A small quantity of enzymes can be used to bring about a large amount of chemical reaction.
At what conditions do enzymes act best?
Each enzyme acts best at the optimum temperature and pH.
How specific are enzymes in their action?
Enzymes are highly specific in their action.
What is an example of enzyme specificity?
Amylase works on starch only to give simple sugars.
Why are enzymes important for living organisms?
To increase the rate of reactions so that life processes can be sustained.
What is a substrate in the context of enzymes?
A substrate is a molecule/s that get broken down or joined together in the reaction.
What is the lock and key model in enzyme action?
In the lock and key model, the enzyme is the lock, and the reactant is the key.
What is the enzyme-substrate complex?
The enzyme-substrate complex is formed when an enzyme binds to its substrate.
What is a catalyst?
A catalyst is a substance that speeds up the rate of chemical reactions without being changed.
What type of catalysts are used in living organisms?
Enzymes are the catalysts used in living organisms.
How long would it take to digest one meal without enzymes?
Without enzymes, it would take around 2 – 3 weeks to digest one meal.
How long does it take to digest one meal with enzymes?
With enzymes, it takes around 4 hours.
What are some examples of enzymes in the human body? (List)
- Lipase
- Amylase
- Protease
- Lactase
- Pepsin
- Salivary amylase
- Trypsin
Fill in the blank: Enzymes function as _______ catalysts.
[biological]
True or False: Enzymes are changed during the chemical reactions they catalyze.
False
What happens to enzyme activity as pH increases?
Enzyme activity increases because the substrate fits into the active site of the enzyme.
After the optimum pH, enzyme activity decreases due to denaturation.
What is the effect of temperature on enzyme activity?
Increase in temperature increases kinetic energy of the enzyme and substrate, leading to increased enzyme activity up to the optimum temperature.
After the optimum temperature, enzyme activity decreases because the enzyme is denatured.
What is catalase and what is its function?
Catalase is an enzyme present in all living cells that speeds up the breakdown of hydrogen peroxide to oxygen and water.
The amount of oxygen produced can be used to measure enzyme activity.
Why is it better to collect oxygen using a measuring cylinder rather than counting bubbles?
Bubbles might be too fast to count accurately.
Measuring cylinder provides a more precise measurement of oxygen produced.
List the factors that affect enzyme reaction.
- Temperature
- pH
- Enzyme concentration
- Substrate concentration
- Inhibitors
These factors can influence the rate and efficiency of enzyme-catalyzed reactions.
Describe the effect of changes in temperature on enzyme activity.
Increased temperature raises kinetic energy, enhancing enzyme activity until the optimum temperature is reached.
Beyond the optimum temperature, enzyme activity declines due to denaturation.
Fill in the blank: The amount of oxygen produced in the reaction can be used to measure how active the _______ is.
[enzyme]
True or False: Enzyme activity decreases after the optimum pH due to denaturation.
True
Denaturation affects the structure and function of the enzyme.
What defines the optimum temperature for an enzyme?
The temperature at which enzyme activity is maximized before denaturation occurs.
Each enzyme has a specific optimum temperature.
What are inhibitors in the context of enzyme activity?
Substances that reduce or prevent enzyme activity.
Inhibitors can be competitive or non-competitive.
