Enzymes – Biochemistry Questions and
Answers with Verified Solutions
What is the primary function of enzymes in biological systems?
✔✔ Enzymes act as catalysts, speeding up chemical reactions without being consumed in the
process.
How do temperature and pH affect enzyme activity?
✔✔ Enzymes have optimal temperature and pH ranges where they function best; deviations can
lead to reduced activity or denaturation.
What is the active site of an enzyme?
✔✔ The active site is the specific region where substrates bind and undergo a chemical reaction.
How do competitive inhibitors affect enzyme function?
✔✔ Competitive inhibitors compete with substrates for binding to the active site, decreasing the
rate of reaction.
What role does substrate concentration play in enzyme kinetics?
1
,✔✔ Increasing substrate concentration typically increases the rate of reaction until the enzyme is
saturated.
What is an enzyme's turnover number?
✔✔ The turnover number is the maximum number of substrate molecules an enzyme can convert
to product per unit time.
How do allosteric enzymes differ from non-allosteric enzymes?
✔✔ Allosteric enzymes can be activated or inhibited by molecules binding to sites other than the
active site, affecting their activity.
What is the significance of cofactors in enzymatic reactions?
✔✔ Cofactors, which can be metal ions or organic molecules, assist enzymes in catalyzing
reactions.
How do enzymes lower the activation energy of a reaction?
✔✔ Enzymes stabilize the transition state, making it easier for reactants to convert into products.
What is the difference between a holoenzyme and an apoenzyme?
2
, ✔✔ A holoenzyme is an active enzyme with its cofactor(s), while an apoenzyme is the inactive
form without its cofactor.
How does enzyme specificity impact biochemical pathways?
✔✔ Enzyme specificity ensures that only particular substrates are transformed into products,
maintaining the integrity of metabolic pathways.
What happens to an enzyme after it catalyzes a reaction?
✔✔ The enzyme is released unchanged and can catalyze additional reactions with other substrate
molecules.
How does feedback inhibition regulate metabolic pathways?
✔✔ Feedback inhibition occurs when the end product of a pathway inhibits an earlier step,
preventing overproduction of the product.
What is enzyme denaturation, and what causes it?
✔✔ Denaturation is the loss of an enzyme's structure and function due to extreme pH,
temperature, or other denaturing agents.
3
Answers with Verified Solutions
What is the primary function of enzymes in biological systems?
✔✔ Enzymes act as catalysts, speeding up chemical reactions without being consumed in the
process.
How do temperature and pH affect enzyme activity?
✔✔ Enzymes have optimal temperature and pH ranges where they function best; deviations can
lead to reduced activity or denaturation.
What is the active site of an enzyme?
✔✔ The active site is the specific region where substrates bind and undergo a chemical reaction.
How do competitive inhibitors affect enzyme function?
✔✔ Competitive inhibitors compete with substrates for binding to the active site, decreasing the
rate of reaction.
What role does substrate concentration play in enzyme kinetics?
1
,✔✔ Increasing substrate concentration typically increases the rate of reaction until the enzyme is
saturated.
What is an enzyme's turnover number?
✔✔ The turnover number is the maximum number of substrate molecules an enzyme can convert
to product per unit time.
How do allosteric enzymes differ from non-allosteric enzymes?
✔✔ Allosteric enzymes can be activated or inhibited by molecules binding to sites other than the
active site, affecting their activity.
What is the significance of cofactors in enzymatic reactions?
✔✔ Cofactors, which can be metal ions or organic molecules, assist enzymes in catalyzing
reactions.
How do enzymes lower the activation energy of a reaction?
✔✔ Enzymes stabilize the transition state, making it easier for reactants to convert into products.
What is the difference between a holoenzyme and an apoenzyme?
2
, ✔✔ A holoenzyme is an active enzyme with its cofactor(s), while an apoenzyme is the inactive
form without its cofactor.
How does enzyme specificity impact biochemical pathways?
✔✔ Enzyme specificity ensures that only particular substrates are transformed into products,
maintaining the integrity of metabolic pathways.
What happens to an enzyme after it catalyzes a reaction?
✔✔ The enzyme is released unchanged and can catalyze additional reactions with other substrate
molecules.
How does feedback inhibition regulate metabolic pathways?
✔✔ Feedback inhibition occurs when the end product of a pathway inhibits an earlier step,
preventing overproduction of the product.
What is enzyme denaturation, and what causes it?
✔✔ Denaturation is the loss of an enzyme's structure and function due to extreme pH,
temperature, or other denaturing agents.
3
