Question

practice: putting it all together (enzymes) answer the following questions. 1. what macromolecule is an enzyme? 2. what is a substrate? 3. what is an active site? 4. how do the terms enzyme, substrate, and active site relate to each other? you may draw a picture if it helps. 5. draw an example of the lock and key model, showing a chemical reaction that forms 1 product from 2 reactants. 6. sketch two energy diagrams. energy diagram a should be endothermic. energy diagram b should be exothermic. add an enzyme to energy diagram b. on each of these diagrams, make sure to label the axes, reactants, products, activation energy, and enzyme (on b only.) 7. real world connection: most enzymes in the human body work best at 37°c (98.6°f.) what do you think this means then when you are sick? 8. real world connection: in relation to your answer to number 7, pretend scientists discover an enzyme in the human body that works best at 39°c. what processes do you think this enzyme is most likely involved in?

Explanation:

1. Enzymes are proteins. Proteins are one of the four major macromolecules in living organisms.
2. A substrate is a molecule upon which an enzyme acts. The enzyme - substrate complex is formed when the substrate binds to the enzyme.
3. An active site is a region on the surface of an enzyme where the substrate binds and the chemical reaction occurs.
4. The enzyme has an active site to which the specific substrate binds. The binding of the substrate to the active site forms an enzyme - substrate complex, which then undergoes a chemical reaction to form products.
5. In the lock - and - key model, the enzyme (lock) has a specific shape that fits the substrate (key) precisely. For a reaction with two reactants forming one product, the two reactant molecules bind to the active site of the enzyme, react, and then the product is released.
6. In an endothermic reaction, the products have higher energy than the reactants. In an exothermic reaction, the products have lower energy than the reactants. When an enzyme is added to an exothermic reaction, it lowers the activation energy. The x - axis of an energy diagram is the reaction progress, and the y - axis is the energy.
7. When sick, body temperature may change. If it is above or below 37°C, the activity of most enzymes may be affected. Enzyme activity may decrease, which can slow down metabolic processes.
8. Since 39°C is higher than normal body temperature (37°C), this enzyme may be involved in processes that occur during fever or in areas of the body with higher - than - normal temperatures, such as during an immune response or in certain metabolic processes that generate heat.

Answer:

1. Protein
2. A molecule on which an enzyme acts.
3. A region on an enzyme where the substrate binds and reaction occurs.
4. The enzyme has an active site for substrate binding to form an enzyme - substrate complex for reaction.
5. Draw an enzyme with a specific - shaped active site where two reactant molecules fit, react, and one product molecule is formed and released.
6. For endothermic diagram: Reactants at lower energy, products at higher energy, large activation energy. For exothermic diagram: Reactants at higher energy, products at lower energy, lower activation energy with enzyme added. Label x - axis as reaction progress and y - axis as energy.
7. Enzyme activity may be affected as body temperature changes from 37°C, potentially slowing metabolic processes.
8. Processes during fever or in heat - generating metabolic/immune responses.