Enzyme Essentials Quiz Answer Key

Here are the answers and explanations for the Enzyme Essentials Quiz.

1. What are enzymes mostly made of?

Correct Answer: Proteins

• Thought Process: Enzymes are biological catalysts, and nearly all enzymes are proteins. Their complex 3D structures are essential for their function.

2. What is the main job of an enzyme?

Correct Answer: To speed up chemical reactions

• Thought Process: Enzymes are catalysts. They lower the activation energy of reactions, significantly increasing the rate at which they occur without being consumed in the process.

3. What do we call the molecule an enzyme acts upon?

Correct Answer: Substrate

• Thought Process: The reactant in an enzyme-catalyzed reaction is called the substrate. The enzyme binds to the substrate to facilitate the reaction.

4. Where does the substrate bind on an enzyme? (Imagine a lock and key)

Correct Answer: The active site

• Thought Process: The active site is a specific region on the enzyme where the substrate molecules bind and undergo a chemical reaction. It's often compared to a lock where the substrate is the key.

5. What happens to an enzyme after it helps a reaction?

Correct Answer: It can be used again

• Thought Process: Enzymes are not consumed or permanently altered during the reactions they catalyze. They are released and can be used to catalyze the same reaction again.

6. What does it mean if an enzyme is 'denatured'?

Correct Answer: It changes shape and stops working

• Thought Process: Denaturation refers to the process where an enzyme loses its specific 3D shape, particularly its active site, often due to extreme conditions (like heat or pH). This loss of shape means it can no longer bind to its substrate and function properly.

7. What can cause an enzyme to denature?

Correct Answer: Extreme heat or pH

• Thought Process: Enzymes are very sensitive to their environment. Temperatures that are too high or pH levels that are too acidic or basic can disrupt the weak bonds holding the enzyme's specific shape, leading to denaturation.

8. Which of these is like a 'helper' molecule for some enzymes?

Correct Answer: Coenzyme

• Thought Process: Some enzymes require non-protein helper molecules called cofactors to function. If the cofactor is an organic molecule, it's called a coenzyme (e.g., vitamins).

9. Enzymes are specific. What does this mean?

Correct Answer: They only work on certain substrates

• Thought Process: Enzyme specificity means that each enzyme typically catalyzes only one or a very small number of reactions, acting on only one or a few closely related substrates. This is due to the unique shape of their active site.

10. What is the 'optimum' condition for an enzyme?

Correct Answer: When it works best and fastest

• Thought Process: The optimum condition (temperature, pH) is the environment where an enzyme exhibits its maximum activity. Deviations from this optimum can decrease efficiency or cause denaturation.

11. Which organ in your body produces many digestive enzymes?

Correct Answer: Stomach and Pancreas

• Thought Process: The stomach produces enzymes like pepsin, and the pancreas produces a wide range of digestive enzymes (amylase, lipase, trypsin) that are crucial for breaking down food in the small intestine.

12. Imagine an enzyme working. What do we call the new molecules formed after the reaction?

Correct Answer: Products

• Thought Process: In a chemical reaction, substrates are converted into products. Enzymes facilitate this conversion.

13. Why is maintaining a stable internal body temperature important for enzyme function?

Correct Answer: To prevent enzymes from denaturing

• Thought Process: Human enzymes are optimized to work at body temperature (around 37°C). Significant deviations, especially increases, can cause enzymes to denature and lose function, which is why fever can be dangerous.

14. What is the 'lock and key' model used to describe?

Correct Answer: How enzymes bind to specific substrates

• Thought Process: The lock and key model explains enzyme specificity, where the substrate (key) fits perfectly into the active site of the enzyme (lock).

15. An enzyme ends with which common suffix?

Correct Answer: -ase

• Thought Process: Most enzymes are named by adding the suffix "-ase" to the name of the substrate they act upon (e.g., lactase breaks down lactose) or the type of reaction they catalyze.