Enzymes
True or False: Enzymes make reactions possible by raising the activation energy.
False. Enzymes lower the activation energy.
True or False: Enzymes work best at any temperature.
False. Each enzyme has an optimal temperature.
True or False: Oxidation always involves oxygen.
False – Oxidation is the loss of electrons, not necessarily involving oxygen.
What do ATP and ADP stand for, and what do they do in the cell?
ATP stands for Adenosine Triphosphate. It is the main energy carrier in cells. It stores energy in the bonds between its three phosphate groups.
ADP stands for Adenosine Diphosphate. It is what’s left when ATP loses one phosphate group to release energy.
What is the role of enzymes in digestion? Give one example.
Enzymes break down large food molecules into smaller ones for absorption. Example: Amylase breaks down starch into glucose in the mouth and small intestine.
Are enzymes consumed or used up during a chemical reaction? Why or why not?
No, enzymes are not used up during a chemical reaction. They act as biological catalysts, meaning they speed up the reaction without being changed or permanently altered themselves.
In a redox reaction, the substance that gets reduced acts as what?
The oxidizing agent.
What process converts ADP back to ATP?
Why do reactions happen faster when an enzyme is present?
Because the enzyme lowers the activation energy, making it easier for the reaction to occur.
How does substrate concentration affect enzyme activity?
As substrate concentration increases, enzyme activity rises until all active sites are occupied (saturation point). Beyond this, adding more substrate doesn’t increase the rate.
Think of a situation in a classroom that could represent a redox reaction. Describe the roles of oxidation and reduction using this analogy.
Loss of Electrons is Oxidation
Gain of Electrons is Reduction
In your own words, create an analogy that explains how the ATP-ADP cycle works.
Like a battery, a phone, or a machine) to help describe how ATP stores and releases energy in cells.
An enzyme is like a dating app algorithm. How does this analogy relate to enzyme specificity?
The algorithm matches people based on compatibility. If the substrate doesn't "match" the enzyme's active site, the reaction won't occur, just like a mismatched pair won't be suggested by the app.
Anna and Bea both eat a bowl of ice cream. Anna feels fine, but Bea experiences bloating and stomach cramps shortly after. Why does Bea react differently to the same food, even though both are healthy individuals?
Bea likely has lower levels of the enzyme lactase, which is needed to break down lactose (milk sugar).
Why is photosynthesis classified as a redox reaction, and which substances undergo oxidation and reduction?
Water (H₂O) is oxidized: It loses electrons during the light-dependent reactions, producing oxygen gas (O₂).
Carbon dioxide (CO₂) is reduced: It gains electrons and hydrogen atoms during the Calvin cycle, forming glucose (C₆H₁₂O₆).
A student gets a small cut on their hand. How does the ATP-ADP cycle support the healing process at the cellular level?
Cells need energy to divide and produce proteins for tissue repair. ATP provides this energy. As ATP is used, it becomes ADP, which is then recharged into ATP using energy from nutrients, continuing the cycle.