Chapter 3: Enzymes Flashcards
What is the role of enzymes in biochemical pathways?
Enzymes act as catalysts, speeding up chemical reactions in important biochemical pathways.
What percentage of the global population is estimated to have a reduced ability to digest lactose?
Approximately 65% of the global population.
What are the key factors affecting enzyme activity
Temperature, pH, and enzyme inhibitors
How do enzymes influence the complex chemical reactions of photosynthesis and cellular respiration?
Enzymes catalyze these reactions
What is the definition of an enzyme?
An organic molecule, typically a protein, that catalyzes specific reactions
What happens to enzymes after catalyzing a reaction?
Enzymes remain unchanged and can catalyze future reactions; they are reusable
What is the active site of an enzyme?
The area to which the substrate binds, allowing the reaction to occur
How do enzymes lower the activation energy of reactions?
Enzymes bring reactants closer to the state needed for the reaction, reducing the size of the activation energy hurdle
Why does lactose intolerance occur?
It is a result of an enzyme deficiency, specifically a decrease in lactase levels as individuals age
How is lactose broken down in individuals with lactose intolerance?
Without lactase, lactose is broken down by probiotic bacteria, producing gas and causing symptoms like bloating and diarrhea
What is a catabolic reaction, and what does it involve?
Catabolic reactions break down large molecules into smaller ones, releasing energy in the process. Examples include digestion and cellular respiration.
EXERGONIC - releases energy
- Define an anabolic reaction and provide examples.
Anabolic reactions build larger molecules from smaller ones, requiring energy. Examples include protein synthesis and photosynthesis.
ENDOGONIC - requires energy
- What is activation energy in a chemical reaction?
coActivation energy is the minimum energy needed for a chemical reaction to occur.
Describe the process of enzyme action and the role of active sites.
Enzymes, proteins with active sites, catalyze reactions by attracting substrates, inducing stress for bond-breaking, and forming products. Active sites are crucial for enzyme specificity.
Explain the role of coenzymes and cofactors in enzyme-catalyzed reactions. Provide examples.
Coenzymes (e.g., ATP, NADH) and cofactors (inorganic/organic) assist enzymes by transferring energy. Examples include metallic ions and vitamins.
What is the significance of pH and temperature in enzyme activity?
Enzymes function optimally within specific pH and temperature ranges. Extremes can denature enzymes, affecting their efficiency.
- How does substrate concentration influence enzyme reaction rates?
Increasing substrate concentration enhances reaction rates until saturation, where all active sites are occupied.
Differentiate between reversible and irreversible enzyme inhibition.
Reversible inhibition is temporary (competitive/non-competitive), while irreversible inhibition permanently deactivates enzymes. (form unbrekable covalent bonds)
Explain the lock and key model and induced fit model of enzyme-substrate interaction.
The lock and key model symbolize specific substrate-enzyme binding, while the induced fit model involves shape changes for better interaction.
What are the factors affecting enzyme activity?
pH, temperature, enzyme concentration, substrate concentration, and inhibition are factors influencing enzyme activity. Each factor plays a critical role in enzyme function.
